Fig 5 - uploaded by Andrew N Iwaniuk
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The graphs shown here indicate the relative size of the Purkinje cell layer of each of the cerebellar folia expressed as a proportion of total Purkinje cell layer volume measured by the length of the Purkinje cell layer throughout the medio-lateral extent of the cerebellum. The fi rst plot ( A ) are the mean proportions of the total volume of the Purkinje cell layer of the anterior (I–V) and posterior lobes (VI–IXcd). The next three histograms show the mean proportions of the total volume of the Purkinje cell layer that each folia comprises within the following: B anterior lobe (folia I–V); C folia VI–VIII; and D folia IXab, IXcd and X. Where more than one species or specimen was examined, a standard error bar is provided. Numbers in parentheses refer to the number of species sampled for those groups with error bars.
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Interspecific variation in the structure of the avian cerebellum is poorly understood. We present the first comparison of cerebellar morphology within the avian order Caprimulgiformes. Using a range of qualitative descriptions and quantitative measurements of cerebellar morphology we compared caprimulgiform birds with hummingbirds and swifts (Apodi...
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... in the volume measures largely sup- ports our observations based upon midsagittal sections only (see above). Figure 5 A is a scatter plot of the propor- tional sizes of the posterior lobe volumes against the an- terior lobe volumes. Corroborating our observations of the midsagittal measures, the apodiforms, nightjars, po- too and owlet-nightjar all have relatively small anterior lobes and relatively large posterior lobes, whereas the op- posite is true of the oilbird, owls and frogmouth. ...
Citations
... However, studies focusing on amphibian brains are still scarce, compared to fishes, birds, and mammals (Arendt et al. 2004, Cañestro et al. 2005, Iwaniuk et al. 2005, Denes et al. 2007, Gonda et al. 2013, O'Donnell et al. 2018. Although the number of studies investigating the evolutionary relationship between brain features and their functions in amphibians is limited, they have found interesting results. ...
... However, in the last few years, studies conducted on other vertebrate lineages, such as mammals, birds, and squamates, revealed promising results comparing brain morphology and species' behaviour (e.g. Iwaniuk et al. 2005, 2006, Ahrens 2014, Macrì et al. 2019, Macrì and Di-Poï 2020. Iwaniuk and Hurd (2005), for instance, categorized different brain morphologies that have presumably evolved in convergence among different bird lineages. ...
... Iwaniuk et al. 2005, 2006, Ahrens 2014, Macrì et al. 2019, Macrì and Di-Poï 2020. Iwaniuk and Hurd (2005), for instance, categorized different brain morphologies that have presumably evolved in convergence among different bird lineages. The authors showed that brain morphology was related to locomotion mode, prey capture, and cognition. ...
The correlation of ecological and behavioural characteristics with morphological features of brain structures has been recurrently corroborated for different vertebrate taxa, such as mammals, birds, and fishes. Here, we asked whether such correlations can also be detected in amphibians, an animal group of great interest due to its great behavioural and ecological diversity. We analysed the shape of two brain regions, cerebellum and optic tectum, of 67 species from 32 families of the order Anura (frogs and toads), applying 2D geometric morphometrics in a phylogenetic context. We found species that share similar environments and daily patterns have a similarly shaped cerebellum and optic tectum, with diurnal and arboreal species with more varied brain shapes. We did not find a correlation between activity mode or lifestyle with shape for both brain regions; however, we found that shared ancestry had an influence in their evolution. Future studies including a higher number of species from each ecological group, and from more families, would help to better clarify whether the patterns found here are a general rule for anurans.
... capability. Also, they are the most emphasized cells in cognitive and behavioral studies [11,12]. Assessments of genetic diversity of farm animals allow breeders to identify, choose, and develop new breeds to face the changing conditions of climate, human needs of nutrition, and disease threats [13]. ...
... Iwaniuk et al. [12] recorded that altricial strains would have higher degrees of foliation and thus cortex width than precocial strains, and those longer periods of embryonic and postembryonic development will be positively correlated with the cortex width. The indicated higher thickness of cerebellar cortex of Balady strain compared to Gamey and Australy strains could refer to the longer time required by hatched Balady for parent's care. ...
... Iwaniuk et al. [12] explained that cognitive ability, managing functional activity, and behavioral complexity increase as a result of increasing number of Purkinje cell. This may reveal that Balady strain had the least cognitive ability if compared to the other studied strains. ...
The present study focused on the variations of morphological and cerebellar histological structures of five strains of adult male Columba livia domestica (n = 5) and their genetic polymorphism using RAPD-PCR technique to differentiate between them and find the best strains that can adapt to different circumstances. In each strain, the beak length and the eye diameter were measured in relation to the head length. Specimens of the cerebellum were fixed and processed for histological investigations. The thickness of the cerebellar cortex layers and the numbers of Purkinje cells was determined. For genetic polymorphism, 20 RAPD primers were used to determine the genetic diversity between the studied strains. Balady strain could express the best adaptation if subjected to feed restrictions; however, its low Purkinje cells number may reveal its low cognitive ability compared to the other studied strains. Primers OPA-1, OPA-3, and OPA-6 are the best used primers to differentiate between the studied strains. The highest similarity coefficient was detected between Halaby and Gamey strains, while, Balady strain was completely separated and independent. In conclusion, in addition to the morphological and histological variations between studied strains, the RAPD markers are recommended as a valuable tool to verify the genetic polymorphism of Columba livia domestica strains.
... l. domestica) consists of two areas: the pallium and the subpallium. The pallium is made up of hyperpallium and the dorsolateral corticoid area large size, in contrast to kiwi, and poto, this area is usually very small, or reduced (10). This layer is divided into several sublayers, consisting of reticular fibers sub layer that is composed of retinal fibers, horizontal neurons that appear to predominate in this layer, neuroglial cells and spherical neurons, and few numbers of fusiform cell the layer appicale hypopallium. ...
The present study deals with the morphological and histological aspects of the forebrain(Cerebrum) in the Columba livia domestica (Gmelin, 1789) to identify the histoarchitecture of its layers. This bird' has a large head found as perpendicular to the longitudinal axis. The morphological results reveal that for brain (Cerebrum) pear shaped, its outer surface is smooth without folds or deep grooves. Cerebrum is made up of two regions, the Pallium and the Subpallium. The Cerebral cortex includes four layers of hyperpallium (Wulst), Dorsolateral corticoid area (CDL), Hippocampus, Piriform cortex. The internal cortex of cerebrum consists of Dorsal Ventricle ridge which includes the mesopallium, nidopallium, and archospallium. All these regions includes Pyramidal cells, which have different sizes and densities, as well as many other neurons and Neuralgial. The Subpallium is divided to Striatum which is consisted of nerve fibers of nerve cells and the Palldium, which is the deepest part of the brain with light- color.
... l. domestica) consists of two areas: the pallium and the subpallium. The pallium is made up of hyperpallium and the dorsolateral corticoid area large size, in contrast to kiwi, and poto, this area is usually very small, or reduced (10). This layer is divided into several sublayers, consisting of reticular fibers sub layer that is composed of retinal fibers, horizontal neurons that appear to predominate in this layer, neuroglial cells and spherical neurons, and few numbers of fusiform cell the layer appicale hypopallium. ...
The present study deals with the morphological and histological aspects of the forebrain(Cerebrum) in the Columba livia domestica (Gmelin, 1789) to identify the histoarchitecture of its layers. This bird' has a large head found as perpendicular to the longitudinal axis. The morphological results reveal that for brain (Cerebrum) pear shaped, its outer surface is smooth without folds or deep grooves. Cerebrum is made up of two regions, the Pallium and the Subpallium. The Cerebral cortex includes four layers of hyperpallium (Wulst) , Dorsolateral corticoid area (CDL), Hippocampus, Piriform cortex. The internal cortex of cerebrum consists of Dorsal Ventricle ridge which includes the mesopallium, nidopallium, and archospallium. All these regions includes Pyramidal cells, which have different sizes and densities, as well as many other neurons and Neuralgial. The Subpallium is divided to Striatum which is consisted of nerve fibers of nerve cells and the Palldium, which is the deepest part of the brain with light- color.
... In amphibians, an increase in cerebellum size has been correlated with arboreality (Taylor et al., 1995). Finally, in birds, an enlarged cerebellum has been correlated with activity patterns, habitat complexity, and behavioral repertoire (Boire and Baron, 1994;Day et al., 2005;Iwaniuk et al., 2006b;Larsell, 1967;Sultan, 2005). ...
In this chapter we provide a description of the cerebellum in nonmammalian vertebrates. This includes comparative aspects of gross morphology, connectivity in the cerebellar cortex, and the organization of sagittal zones. We also examine variation in the degree of foliation of the cerebellum among species in relation to behavior and neural processing. Finally, we outline differences in the distribution of the expression of the molecular marker zebrin II by Purkinje cells and its implications for cerebellar evolution.
... Similarly, mammalian isocortical gyrification closely correlates with both brain and isocortex size [Zilles et al., 1989;Carlson, 1991;Striedter, 2005]. Most studies have also asserted that cognitive and/or behavioral differences play a role in the evolution of the cerebellum, ranging from electrosensory-electromotor specialization in mormyrids to cognitive motor behaviors in birds and mammals, in addition to phylogenetic and allometric effects [Bell and Szabo, 1986;Demaerel, 2002;Sultan, 2005;Iwaniuk et al., 2006bIwaniuk et al., , 2009Sultan and Glickstein, 2007;Zhang et al., 2011;Hall et al., 2013]. ...
A true cerebellum appeared at the onset of the chondrichthyan (sharks, batoids, and chimaerids) radiation and is known to be essential for executing fast, accurate, and efficient movement. In addition to a high degree of variation in size, the corpus cerebellum in this group has a high degree of variation in convolution (or foliation) and symmetry, which ranges from a smooth cerebellar surface to deep, branched convexities and folds, although the functional significance of this trait is unclear. As variation in the degree of foliation similarly exists throughout vertebrate evolution, it becomes critical to understand this evolutionary process in a wide variety of species. However, current methods are either qualitative and lack numerical rigor or they are restricted to two dimensions. In this paper, a recently developed method for the characterization of shapes embedded within noisy, three-dimensional data called spherical wave decomposition (SWD) is applied to the problem of characterizing cerebellar foliation in cartilaginous fishes. The SWD method provides a quantitative characterization of shapes in terms of well-defined mathematical functions. An additional feature of the SWD method is the construction of a statistical criterion for the optimal fit, which represents the most parsimonious choice of parameters that fits to the data without overfitting to background noise. We propose that this optimal fit can replace a previously described qualitative visual foliation index (VFI) in cartilaginous fishes with a quantitative analog, i.e. the cerebellar foliation index (CFI). The capability of the SWD method is demonstrated in a series of volumetric images of brains from different chondrichthyan species that span the range of foliation gradings currently described for this group. The CFI is consistent with the qualitative grading provided by the VFI, delivers a robust measure of cerebellar foliation, and can provide a quantitative basis for brain shape characterization across taxa.
... It was mentioned that its shape and size are related to extremity movements, gravity centre, and species posture (Mondal, 1997, Mial andReckess, 2002). Two morphological features of the cerebellum are the variation in both its volume and foliation (amount of surface folding) between species: amphibians and reptiles have unfolded cerebella while birds and mammals have variably convoluted cerebella (Larsell, 1967 andIwaniuk et al., 2006). Zachary et al. (2013) suggest that increasing cerebellar foliation may be allowing improved motor control and increasingly complex behaviours. ...
... Differences in volume, morphology, and histology of the cerebellum appear to relate to the performance of other types of tasks, and some differences are known to exist according to species, general anatomic structure and behavioural features (Mondal, 1997, Mial and Reckess, 2002and Iwaniuk et al., 2006. The present study revealed that the dorsal surface of the cerebellum in camel has many Studies on the cerebellun of the dromedary Rasha Beheiry folia separated by sulci grooves. ...
htiW 8 strugif rieitvid neiecigl beeiciid seg cuc,tebitee deviecig 2015 Abstract Little researches are known about the cerebellum of camel. This work aimed to study the morphology and histology of the cerebellum in ten camels by using histological paraffin sections and scanning electron microscope. Also, avidin-biotin complex peroxi-dase (ABC) method for the demonstration of glial fibrillary acidic protein (GFAP), and S-100 protein. The results revealed that the cerebel-lum was formed from cortex and me-dulla. The cerebellar cortex consists of three layers, outer molecular layer, middle Purkinje cell layer and inner granular layer. The immunohisto-chemical findings show that S100 and GFAP immunoreactivity was found in the three layers of cerebellar cortex and in the medulla. The cells of the molecular layer, Purkinje cells and the granule cells were immunostained with anti-S-100 protein, in addition the glia cells and their processes, which were detected in form of network were also strongly immunostained. GFAP immunoreactivity in the molec ular layer was detected but less dense than S100-immunereactivity. The Purkinje cells were surrounded by brown network of GFAP immuno-reactive glial cells. In the granular layer, the GFAP immunoreactivity showed similar reaction to those of S100-immunoreactivity. Scanning electron microscopic findings rvealed that the dorsal surface of the cerebel-lum showed two elevated ridges (fo-lia) in between groove (sulci). The dorsal surface of cerebellar cortex showed a corrugation, which resembles the irregular bleb like protrusions. Conclusions: the results obtained from this study revealed that the cer-ebellum of camel contains immunore-active S100 protein and GFAP.
... Sekerkova et al. (2004) found that, bromo-deoxyuridine causes remarkable defects in the generation, migration, and sett- ling of the Purkinje cells, also it reduces the size of the cerebellar cortex and leads to designation disorders of cerebellar foliation. Iwaniuk et al. (2006) recorded that, most of birds have nine cerebellar folia that varied in their length, thickness, subdivision into secondary folia according to their taxa. They also added that, the divergence of this foliation among birds reflect their behavior. ...
Long-acting nicotine is known to exert pathological effects on almost all tissues including the cerebellar cortex. The present work was designed to elucidate the effect of nicotine on the development of cerebellar cortex of chick embryo during incubation period.
The fertilized eggs of hen (Gallus gallus domesticus) were injected into the air space by a single dose of long acting nicotine (1.6 mg/kg/egg) at the 4th day of incubation. The embryos were taken out of the eggs on days 8, 12 and 16 of incubation. The cerebellum of the control and treated embryos at above ages were processed for histopathological examination. The TEM were examined at 16th day of incubation.
The results of the present study revealed that, exposure to long-acting nicotine markedly influence the histogenesis of cerebellar cortex of chick embryo during the incubation period. At 8th day of incubation, nicotine delayed the differentiation of the cerebellar analge; especially the external granular layer (EGL) and inner cortical layer (ICL). Furthermore, at 12th day of incubation, the cerebellar foliation was irregular and the Purkinje cells not recognized. By 16th day of incubation, the cerebellar foliations were irregular with interrupted cerebellar cortex and irregular arrangement of Purkinje cells.
Immunohistochemical analysis for antibody P53 protein revealed that the cerebellar cortex in all stages of nicotine treated groups possessed a moderate to weak reaction for P53 protein however; this reaction was markedly stronger in the cerebellar cortex of control groups. Moreover, the flow cytometric analysis confirmed that the percentage of apoptosis in control group was significantly higher compared with that of nicotine treated group.
At the TEM level, the cerebellar Purkinje cells of 16th day of treated groups showed multiple subcellular alterations in compared with those of the corresponding control group. Such changes represented by appearing of vacuolated mitochondria, cisternal fragmentation of RER, irregular grooves of Golgi tubules. Also, multiple cytoplasmic vacuoles and aggregation of Nissl granules were recorded around pyknotic nucleus.
... If so, the apparently large flocculi of birds may actually be an expression of a functionally enlarged flocculus-uvula-nodulus complex. A comparison of vestibulocerebellar size, the combination of the uvula and nodulus, across extant birds suggests that the uvulanodulus is smaller in 'strong fliers' [51], which were a collection of species defined by Larsell [52] as species that fly long distances or are highly maneuverable and included a diverse array of taxa (waterfowl, swifts, raptors, hummingbirds, seabirds, terns, penguins and swallows). A more accurate categorization of flight behavior as well as a survey of floccular volumes would provide some insight into whether uvula-nodulus expansion is related to floccular expansion and the relationship that both have to flight behavior, if any. ...
Extinct animal behavior has often been inferred from qualitative assessments of relative brain region size in fossil endocranial casts. For instance, flight capability in pterosaurs and early birds has been inferred from the relative size of the cerebellar flocculus, which in life protrudes from the lateral surface of the cerebellum. A primary role of the flocculus is to integrate sensory information about head rotation and translation to stabilize visual gaze via the vestibulo-occular reflex (VOR). Because gaze stabilization is a critical aspect of flight, some authors have suggested that the flocculus is enlarged in flying species. Whether this can be further extended to a floccular expansion in highly maneuverable flying species or floccular reduction in flightless species is unknown. Here, we used micro computed-tomography to reconstruct ''virtual'' endocranial casts of 60 extant bird species, to extract the same level of anatomical information offered by fossils. Volumes of the floccular fossa and entire brain cavity were measured and these values correlated with four indices of flying behavior. Although a weak positive relationship was found between floccular fossa size and brachial index, no significant relationship was found between floccular fossa size and any other flight mode classification. These findings could be the result of the bony endocranium inaccurately reflecting the size of the neural flocculus, but might also reflect the importance of the flocculus for all modes of locomotion in birds. We therefore conclude that the relative size of the flocculus of endocranial casts is an unreliable predictor of locomotor behavior in extinct birds, and probably also pterosaurs and non-avian dinosaurs.
... Comparing cluster dendrograms with a phylogeny of the species of interest can reveal whether interspecific variation is largely attributable to phylogenetic relatedness or to some ecological or behavioral factor(s) [Iwaniuk and Hurd, 2005]. This approach has been widely used in comparative studies of avian neuroanatomy [Rehkamper et al., 2003;Iwaniuk and Hurd, 2005;Iwaniuk et al., 2006;GutiérrezIbáñez et al., 2011], including studies on the visual system [Partridge, 1989;Hart, 2001]. We compared cluster dendrograms to the owl phylogeny studied by Wink et al. [2008], which represents the most complete molecular phylogeny for owls currently available. ...
The eyes of vertebrates show adaptations to the visual environments in which they evolve. For example, eye shape is associated with activity pattern, while retinal topography is related to the symmetry or 'openness' of the habitat of a species. Although these relationships are well documented in many vertebrates including birds, the extent to which they hold true for species within the same avian order is not well understood. Owls (Strigiformes) represent an ideal group for the study of interspecific variation in the avian visual system because they are one of very few avian orders to contain species that vary in both activity pattern and habitat preference. Here, we examined interspecific variation in eye shape and retinal topography in nine species of owl. Eye shape (the ratio of corneal diameter to eye axial length) differed among species, with nocturnal species having relatively larger corneal diameters than diurnal species. All the owl species have an area of high retinal ganglion cell (RGC) density in the temporal retina and a visual streak of increased cell density extending across the central retina from temporal to nasal. However, the organization and degree of elongation of the visual streak varied considerably among species and this variation was quantified using H:V ratios. Species that live in open habitats and/or that are more diurnally active have well-defined, elongated visual streaks and high H:V ratios (3.88-2.33). In contrast, most nocturnal and/or forest-dwelling owls have a poorly defined visual streak, a more radially symmetrical arrangement of RGCs and lower H:V ratios (1.77-1.27). The results of a hierarchical cluster analysis indicate that the apparent interspecific variation is associated with activity pattern and habitat as opposed to the phylogenetic relationships among species. In seven species, the presence of a fovea was confirmed and it is suggested that all strigid owls may possess a fovea, whereas the tytonid barn owl (Tyto alba) does not. A size-frequency analysis of cell soma area indicates that a number of different RGC classes are represented in owls, including a population of large RGCs (cell soma area >150 µm(2)) that resemble the giant RGCs reported in other vertebrates. In conclusion, eye shape and retinal topography in owls vary among species and this variation is associated with different activity patterns and habitat preferences, thereby supporting similar observations in other vertebrates.
