Dendrites of spiny stellate neurons increase complexity while remodeling within the first month of life. (A) Representative camera lucida drawings from spiny stellate neurons within layer IV of the primary somatosensory barrel cortex. The drawings represent neurons at postnatal day (PD) 5, 15 and 25. Scale bar 40 μm. (B-D) Box-and-whisker plots of dendritic arbors, indicating the mean (squares), 25th percentile (bottom line), median (middle line), 75th percentile (top line), 5th and 95th percentile (whiskers), and minimum and maximum measurements (x). Morphometric analysis of spiny stellate dendritic arbors was performed by counting total dendritic arbor branch number (B), total dendritic arbor length (C), and dendritic arbor fractal dimension (D) at PD5, PD10, PD15 and PD25. Numbers in parenthesis represent the number of dendritic arbors measured for each condition. 5 rats were used per age. Dendritic arbor branch number per order (E) and dendritic arbor branch length per order (F) were also measured from the same dendritic arbors at PD5 (open squares), PD15 (close circles), and PD25 (open triangles). 

Contexts in source publication

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

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... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

Context 14

... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

Context 15

... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

Context 16

... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

Context 17

... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

Context 18

... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...

Context 19

... of spiny stellate neurons within layer IV of the primary somatosensory barrel cortex are essential for receiving information from the thalamus. The number of branches in the dendritic arbor reflects the complexity of the thalamocortical pathway. Thus, in order to follow the growth and complexity changes of dendritic arbors of spiny stellate neurons at layer IV of primary somatosen- sory cortex (S1), neurons were identified by Golgi-Cox staining and fifty cells, per age were drawn with the help of a camera lucida. Neurons within the barrel subfield at postnatal day (PD) 5 presented very few branches in the dendritic arbors. Branches were short and single, or poorly ramified (Figure 1A), while neurons at PD15 had many more branches and more complex dendritic arbors ( Figure 1A). Neurons at PD25 had longer dendritic ar- bors with a similar complexity as in PD15. Notably at PD25 the branches were polarized to one side of the cell, probably because the branches were oriented towards the center of the barrel to contact terminal axonal arbors of the thalamus. It is generally accepted that hollows emerge via passive displacement of cortical cells by dense thalamocortical terminal clusters in barrel centers. Additionally, it seems that the emergence of sides and septa are also related to the progressive asymmetry of dendrites from the cells of the barrel side toward the barrel hollow [27]. In order to quantify dendritic arbors at different ages, morphometric analyses of these neurons was performed. Box chart whisker plots were used to show the distribution of total dendritic arbor branch number (Figure 1B), total dendritic arbor length ( Figure 1C), and dendritic arbor fractal dimension ( Figure 1D). Total dendritic arbor branch number increased as the neurons matured, reaching a maximum at PD15 ( Figure 1B). By PD25 the total dendritic arbor branch number seemed to decrease slightly but this difference was not significant ( Figure 1B). Similarly, the total length of dendritic arbors increased as neurons matured, reaching a maximum size at PD25 ( Figure 1C). Also, fractal di- mension of these dendritic arbors increased as the neu- rons matured, and reached a maximum at PD15 ( Figure 1D). By PD25 the fractal dimension remained constant ( Figure 1D). Since total dendritic arbor branch number and total dendritic arbor length did not fully explain complexity; we further examined the level of complexity by determining dendritic arbor branch number and length per order. These parameters reflect the complexity of a circuit and can show the construction of the whole arbor. Dendritic arbors of neurons at PD5 primarily had den- drites of first order, which branched out reaching the fourth order ( Figure 1E). Dendritic arbors of neurons at PD15 showed dendritic branches that reached the ninth order ( Figure 1E). The largest number of dendritic arbor branches were those of the first to the forth order ( Figure 1E). Dendritic arbors of neurons at PD25 showed a similar dendritic arbor branching behavior as PD15 neu- rons, except that ninth order branches were not detected ( Figure 1E). These data suggest that neurons expand dendrite branching within the first 15 days of postnatal life, and indicate that dendrites have more branching close to the soma. In PD5 neurons, first order dendritic branches were the longest and dendritic arbor branch length decreased as the branch order augmented ( Figure 1F). In PD15 neurons, second and third order dendrites were the longest ( Figure 1F). From the forth order the branch length decreased gradually as the order increased ( Figure 1F). In PD25 neurons, second and third order branch dendrites were still the longest ones and also were longer than those present on PD15 neurons ( Figure 1F). Similarly, as in PD15 neurons, the dendritic arbor branch length decreased gradually as the order increased (Fig- ure 1F). These results suggest that as the neurons matured, they initially increased the number and complexity of their dendrites, followed by branch loss across dendrite orders, while they simultaneously increased the length of the remaining ...