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Cell context alters trophic factor modulation of Purkinje cell survival. A, Purkinje cells cultured alone; B, Purkinje cells cocultured with granule cells; C, mixed cultures of whole cerebellum. Purkinje cell survival is represented as a percentage of the Purkinje cell number in untreated, matched control cultures at each time point. Error bars indicate SE. div, Days in vitro. Line, 100% of control cell survival. Asterisk s, Statistically significant differences from untreated control cell survival; *p 0.05; **p 0.01.
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Granule neurons, presynaptic afferents of Purkinje cells, are potent regulators of Purkinje cell development. Purified Purkinje cells survive and differentiate poorly, whereas coculture with granule neurons enhances their survival and dendritic development. Here we investigate the role of neurotrophins in granule-Purkinje cell interactions. BDNF or...
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... factor modulation of Purkinje cell survival was exam- ined using three different cell combinations: Purkinje cells alone, Purkinje cells cocultured with granule neurons, and mixed cere- bellar cells. Cultures were treated with each of four growth factors: NT-3, NT-4, BDNF, and CNTF. The concentration of growth factors used was determined by generating dose-response curves for each cell combination with each growth factor at concentrations ranging from 0.1 to 1000 ng/ml (data not shown). For Purkinje cells cultured alone, 50 ng/ml NT-4 or 10 ng/ml BDNF gave optimal increases in survival relative to those in untreated control cultures at 14 div (Fig. 2 A). In contrast, 50 ng/ml NT-3 or 10 ng/ml CNTF decreased Purkinje cell survival at 6 or 14 div (Fig. 2 A). No higher or lower growth factor concentrations from the dose-response experiments gave greater Purkinje cell survival for any of the three cell combinations. All subsequent experiments were therefore conducted using these concentrations of growth ...
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... factor modulation of Purkinje cell survival was exam- ined using three different cell combinations: Purkinje cells alone, Purkinje cells cocultured with granule neurons, and mixed cere- bellar cells. Cultures were treated with each of four growth factors: NT-3, NT-4, BDNF, and CNTF. The concentration of growth factors used was determined by generating dose-response curves for each cell combination with each growth factor at concentrations ranging from 0.1 to 1000 ng/ml (data not shown). For Purkinje cells cultured alone, 50 ng/ml NT-4 or 10 ng/ml BDNF gave optimal increases in survival relative to those in untreated control cultures at 14 div (Fig. 2 A). In contrast, 50 ng/ml NT-3 or 10 ng/ml CNTF decreased Purkinje cell survival at 6 or 14 div (Fig. 2 A). No higher or lower growth factor concentrations from the dose-response experiments gave greater Purkinje cell survival for any of the three cell combinations. All subsequent experiments were therefore conducted using these concentrations of growth ...
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... on these expression data and on the fact that granule cells are presynaptic to Purkinje cells, we predicted that BDNF signaling would occur in granule-Purkinje cell cocultures and that exogenous BDNF would affect Purkinje cell survival and/or differentiation. Consistent with these predictions, BDNF in- creased the survival of Purkinje cells cultured alone (Fig. 2 A). In contrast, BDNF added to granule cell-Purkinje cell cocultures decreased Purkinje cell survival (Fig. 2 B) beyond levels that might be explained by concomitant loss of granule cells (Table 2), implicating the cellular environment (absence or presence of granule cells) and corresponding levels of BDNF and TrkB ex- pression in determining whether BDNF treatment promotes sur- vival or death of Purkinje ...
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... on these expression data and on the fact that granule cells are presynaptic to Purkinje cells, we predicted that BDNF signaling would occur in granule-Purkinje cell cocultures and that exogenous BDNF would affect Purkinje cell survival and/or differentiation. Consistent with these predictions, BDNF in- creased the survival of Purkinje cells cultured alone (Fig. 2 A). In contrast, BDNF added to granule cell-Purkinje cell cocultures decreased Purkinje cell survival (Fig. 2 B) beyond levels that might be explained by concomitant loss of granule cells (Table 2), implicating the cellular environment (absence or presence of granule cells) and corresponding levels of BDNF and TrkB ex- pression in determining whether BDNF treatment promotes sur- vival or death of Purkinje ...
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... or NT-4 increased survival of Purkinje cells cultured alone (Fig. 2 A). When Purkinje cells were cocultured with gran- ule neurons, their normal presynaptic afferents (Fig. 2 B), or when Purkinje cells were cultured in the presence of mixed cerebellar cells (Fig. 2C), the survival-enhancing effects of NT-4 or BDNF apparent in Purkinje cells cultured alone were counteracted. Although NT-4 in cultures of Purkinje cells alone at 14 div gave 148% of untreated control cell survival, NT-4 in Purkinje-gran- ule cocultures gave only 13% of control cell survival, and NT-4 in mixed cultures gave 29% of control cell survival (Fig. 2). Al- though BDNF in cultures of Purkinje cells alone at 14 div pro- duced 147% of control cell survival, addition of BDNF when granule cells were present reduced Purkinje cell survival to 24% of control levels, and BDNF treatment of mixed cultures reduced Purkinje cell survival to 33% of control levels. NT-3 or CNTF treatment decreased Purkinje cell survival in all cell combina- tions tested (Fig. 2). All combinations of these four growth factors were also tested, but no combination increased Purkinje cell survival above that in the singly treated cultures (data not ...
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... or NT-4 increased survival of Purkinje cells cultured alone (Fig. 2 A). When Purkinje cells were cocultured with gran- ule neurons, their normal presynaptic afferents (Fig. 2 B), or when Purkinje cells were cultured in the presence of mixed cerebellar cells (Fig. 2C), the survival-enhancing effects of NT-4 or BDNF apparent in Purkinje cells cultured alone were counteracted. Although NT-4 in cultures of Purkinje cells alone at 14 div gave 148% of untreated control cell survival, NT-4 in Purkinje-gran- ule cocultures gave only 13% of control cell survival, and NT-4 in mixed cultures gave 29% of control cell survival (Fig. 2). Al- though BDNF in cultures of Purkinje cells alone at 14 div pro- duced 147% of control cell survival, addition of BDNF when granule cells were present reduced Purkinje cell survival to 24% of control levels, and BDNF treatment of mixed cultures reduced Purkinje cell survival to 33% of control levels. NT-3 or CNTF treatment decreased Purkinje cell survival in all cell combina- tions tested (Fig. 2). All combinations of these four growth factors were also tested, but no combination increased Purkinje cell survival above that in the singly treated cultures (data not ...
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... or NT-4 increased survival of Purkinje cells cultured alone (Fig. 2 A). When Purkinje cells were cocultured with gran- ule neurons, their normal presynaptic afferents (Fig. 2 B), or when Purkinje cells were cultured in the presence of mixed cerebellar cells (Fig. 2C), the survival-enhancing effects of NT-4 or BDNF apparent in Purkinje cells cultured alone were counteracted. Although NT-4 in cultures of Purkinje cells alone at 14 div gave 148% of untreated control cell survival, NT-4 in Purkinje-gran- ule cocultures gave only 13% of control cell survival, and NT-4 in mixed cultures gave 29% of control cell survival (Fig. 2). Al- though BDNF in cultures of Purkinje cells alone at 14 div pro- duced 147% of control cell survival, addition of BDNF when granule cells were present reduced Purkinje cell survival to 24% of control levels, and BDNF treatment of mixed cultures reduced Purkinje cell survival to 33% of control levels. NT-3 or CNTF treatment decreased Purkinje cell survival in all cell combina- tions tested (Fig. 2). All combinations of these four growth factors were also tested, but no combination increased Purkinje cell survival above that in the singly treated cultures (data not ...
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... or NT-4 increased survival of Purkinje cells cultured alone (Fig. 2 A). When Purkinje cells were cocultured with gran- ule neurons, their normal presynaptic afferents (Fig. 2 B), or when Purkinje cells were cultured in the presence of mixed cerebellar cells (Fig. 2C), the survival-enhancing effects of NT-4 or BDNF apparent in Purkinje cells cultured alone were counteracted. Although NT-4 in cultures of Purkinje cells alone at 14 div gave 148% of untreated control cell survival, NT-4 in Purkinje-gran- ule cocultures gave only 13% of control cell survival, and NT-4 in mixed cultures gave 29% of control cell survival (Fig. 2). Al- though BDNF in cultures of Purkinje cells alone at 14 div pro- duced 147% of control cell survival, addition of BDNF when granule cells were present reduced Purkinje cell survival to 24% of control levels, and BDNF treatment of mixed cultures reduced Purkinje cell survival to 33% of control levels. NT-3 or CNTF treatment decreased Purkinje cell survival in all cell combina- tions tested (Fig. 2). All combinations of these four growth factors were also tested, but no combination increased Purkinje cell survival above that in the singly treated cultures (data not ...
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... or NT-4 increased survival of Purkinje cells cultured alone (Fig. 2 A). When Purkinje cells were cocultured with gran- ule neurons, their normal presynaptic afferents (Fig. 2 B), or when Purkinje cells were cultured in the presence of mixed cerebellar cells (Fig. 2C), the survival-enhancing effects of NT-4 or BDNF apparent in Purkinje cells cultured alone were counteracted. Although NT-4 in cultures of Purkinje cells alone at 14 div gave 148% of untreated control cell survival, NT-4 in Purkinje-gran- ule cocultures gave only 13% of control cell survival, and NT-4 in mixed cultures gave 29% of control cell survival (Fig. 2). Al- though BDNF in cultures of Purkinje cells alone at 14 div pro- duced 147% of control cell survival, addition of BDNF when granule cells were present reduced Purkinje cell survival to 24% of control levels, and BDNF treatment of mixed cultures reduced Purkinje cell survival to 33% of control levels. NT-3 or CNTF treatment decreased Purkinje cell survival in all cell combina- tions tested (Fig. 2). All combinations of these four growth factors were also tested, but no combination increased Purkinje cell survival above that in the singly treated cultures (data not ...
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... results presented here differ significantly from those al- ready in the literature. Specifically, CNTF was reported to in- crease Purkinje cell survival above untreated controls in mixed cultures from E16 rats ( Larkfors et al., 1994Larkfors et al., , 1996) but decreased Purkinje cell survival under our culture conditions (Fig. 2). BDNF, previously shown to decrease Purkinje cell survival , actually increased survival of purified Pur- kinje cells cultured alone (Fig. 2 A). Comparison of our methods with those used previously revealed several differences that may account for our novel results. Principal among these is use of serum-containing medium, which alters the effects of all the growth factors tested here on Purkinje cells (Fig. 3). Our study included purified cell populations in addition to a mixture of cerebellar cells, and our results highlight the importance of using defined cell populations in unraveling which factors directly con- tribute to Purkinje cell survival and ...
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... results presented here differ significantly from those al- ready in the literature. Specifically, CNTF was reported to in- crease Purkinje cell survival above untreated controls in mixed cultures from E16 rats ( Larkfors et al., 1994Larkfors et al., , 1996) but decreased Purkinje cell survival under our culture conditions (Fig. 2). BDNF, previously shown to decrease Purkinje cell survival , actually increased survival of purified Pur- kinje cells cultured alone (Fig. 2 A). Comparison of our methods with those used previously revealed several differences that may account for our novel results. Principal among these is use of serum-containing medium, which alters the effects of all the growth factors tested here on Purkinje cells (Fig. 3). Our study included purified cell populations in addition to a mixture of cerebellar cells, and our results highlight the importance of using defined cell populations in unraveling which factors directly con- tribute to Purkinje cell survival and ...
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... Purkinje cells cultured alone extend axons but develop only rudimentary, unbranched dendrites resembling the "periso- matic process" stage of Purkinje cells in vivo ( Baptista et al., 1994) ( Fig. 1 A). Purified Purkinje cells cultured with granule neurons elaborate axons and mature, highly branched dendrites bearing spines ( Baptista et al., 1994) (Fig. 1C). Despite the increase in purified Purkinje cell survival with BDNF or NT-4 treatment (Fig. 2 A), none of the growth factors tested triggered develop- ment of mature dendrites in cultures containing only purified Purkinje cells (Fig. 1 B) (data not shown). In neurotrophin- treated cocultures containing Purkinje and granule cells, Purkinje cell survival was reduced relative to untreated controls, but the Purkinje cells that did survive developed dendrites with branch orders similar to those in untreated control cultures (Fig. 1C-F ). BDNF treatment of cocultures seemed to increase spine density ( Fig. 1 E,F ). These results will be detailed in a separate report. Combined with recent data on Purkinje cell development in BDNF / mice ( Schwartz et al., 1997), these effects on spine density imply that BDN F may be required for at least two stages of Purkinje cell dendrite development (see ...
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... test the hypothesis that BDNF in excess of that provided by granule cells becomes toxic to Purkinje cells in granule-Purkinje cell cocultures, either TrkB-IgG fusion protein or anti-BDNF antiserum previously shown to block BDNF signaling ( Ghosh et al., 1994) was added to the culture medium. As in the experiments shown in Figure 2, BDNF treatment decreased the survival of cocultured Purkinje cells relative to that of untreated controls (Fig. 4). TrkB-IgG fusion protein was more efficient than anti- BDNF at rescuing Purkinje cells from BDNF-induced death (Fig. 4). At 6 div, TrkB-IgG increased Purkinje cell survival in BDNF- treated cocultures from 31 to 89% of control survival ( p 0.01). At 14 div, TrkB-IgG increased Purkinje cell survival from 17 (BDNF-only) to 98% (BDNF plus TrkB-IgG) of control survival ( p 0.01). TrkB-IgG alone had little or no effect on Purkinje cell survival (Fig. 4 A). Possible explanations for this result are ex- plored in ...
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... expression patterns of neurotrophins and their receptors within the cerebellum suggest a mechanism for neurotrophin- induced Purkinje cell loss when Purkinje cells are cocultured with their granule cell afferents. Granule cells express BDNF RNA ( Hofer et al., 1990;Rocamora et al., 1993) and TrkB receptors ( Gao et al., 1995;Segal et al., 1995). Purkinje cells, the postsynaptic target of granule cells, do not express RNA encoding BDNF ( Hofer et al., 1990;Rocamora et al., 1993) but do contain BDNF protein (Dugich-Djordjevic et al., 1995) and TrkB receptors ( Gao et al., 1995). Granule cells may therefore normally produce BDNF that is transferred to Purkinje cells, enhancing Purkinje cell survival. Our finding that BDNF in- creases survival of Purkinje cells cultured alone to 147% of the control level (Fig. 2 A), combined with previous findings that granule cells increase survival of Purkinje cells ( Baptista et al., 1994), supports this hypothesis. Under this model, the BDNF- induced decrease in Purkinje cell survival (toxicity) in Purkinje cell-granule neuron cocultures could be attributable to excess, exogenous BDNF beyond the levels of BDNF normally supplied to Purkinje cells by the granule ...
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... growth factor such as BDN F with survival effects on Purkinje cells might be expected to induce their dendritic differentiation. A precedent for single-factor induction of de novo dendrite forma- tion is OP-1, a member of the BMP/TGF family that has striking effects on dendrite outgrowth of sympathetic neurons ( Lein et al., 1995). Indeed, NT-3 was previously reported to increase neurite outgrowth of Purkinje cells in mixed cerebellar cultures ( . Although BDNF and NT4 increased the survival of Purkinje cells cultured alone (Fig. 2 A), none of the neurotrophins tested here was able to induce Purkinje dendrite formation de novo, in the absence of granule cells. These results are consistent with the idea that CNS neurons in general may require a menu of signals for their survival and dendrito- genesis (Meyer-Franke et al., ...
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... cell survival in Purkinje -granule cell cocultures was esti-mated by counting calbindin-D 28k -negative granule cells with phase optics in eight randomly selected field positions using a Leitz Orthoplan microscope with a 63 objective and a camera lucida to mark the counted cells. This sample area contained 2000 -3000 granule cells, representing 1.4% of the total Lab-Tek well surface. The percentage of control granule cell survival was calculated as described for Purkinje cell survival above. Granule cell survival data for glutamate antagonist and TrkB-IgG experiments were collected from at least two wells from each of at least three independent experiments, giving a total well number of at least six for each estimate. Granule cell survival data for anti-BDN F experiments represent five wells from a total of three independent experiments and four wells from two independent experiments, respectively. Statistical anal ysis. Statistical comparisons were performed using the SAS software package or using Microsoft E xcel paired t tests. ANOVA was conducted using the SAS General Linear Models (GL M) procedure, which performs calculations similar to those of the ANOVA procedure but is preferable for data sets containing unequal sample sizes. For Figure 2, raw numbers of surviving Purkinje cells were compared with untreated, matched controls using GL M with Dunnett's t tests. For Figure 3, Purkinje cell survival in growth factor-treated cultures was normalized to a percentage of survival in cultures with serum-free medium, and the differences in survival between serum-containing and serum-free conditions were compared within each growth factor treat- ment using paired t tests. For Figures 4 and 5, raw numbers were converted to a percentage of untreated control cell survival and then compared with survival in BDN F-treated cultures using GL M with Dunnett's t ...
Citations
... Mixed cerebellar cells were isolated from P3 WT and nNOS −/− mice as previously described [33,34] with modifications. Briefly, mouse pups were euthanized by decapitation under isoflurane anesthesia. ...
... Specifically, individual PNs scattered among granule cells. Consistent with previous reports [33,34], PNs represented 1%-3% of cell population in the cultures where the majority were nNOS-expressing GNs [17] that display small round soma. ...
Responding to burst stimulation of parallel fibers (PFs), cerebellar Purkinje neurons (PNs) generate a convolved synaptic response displaying a fast excitatory postsynaptic current (EPSCFast) followed by a slow EPSC (EPSCSlow). The latter is companied with a rise of intracellular Ca²⁺ and critical for motor coordination. The genesis of EPSCSlow in PNs results from activation of metabotropic type 1 glutamate receptor (mGluR1), oligomerization of stromal interaction molecule 1 (STIM1) on the membrane of endoplasmic reticulum (ER) and opening of transient receptor potential canonical 3 (TRPC3) channels on the plasma membrane. Neuronal nitric oxide synthase (nNOS) is abundantly expressed in PFs and granule neurons (GNs), catalyzing the production of nitric oxide (NO) hence regulating PF-PN synaptic function. We recently found that nNOS/NO regulates the morphological development of PNs through mGluR1-regulated Ca²⁺-dependent mechanism. This study investigated the role of nNOS/NO in regulating EPSCSlow. Electrophysiological analyses showed that EPSCSlow in cerebellar slices of nNOS knockout (nNOS−/−) mice was significantly larger than that in wildtype (WT) mice. Activation of mGluR1 in cultured PNs from nNOS−/− mice evoked larger TRPC3-channel mediated currents and intracellular Ca²⁺ rise than that in PNs from WT mice. In addition, nNOS inhibitor and NO-donor increased and decreased, respectively, the TRPC3-current and Ca²⁺ rise in PNs. Moreover, the NO-donor effectively decreased TRPC3 currents in HEK293 cells expressing WT STIM1, but not cells expressing a STIM1 with cysteine mutants. These novel findings indicate that nNOS/NO inhibits TRPC3-containig channel mediated cation influx during EPSCSlow, at least in part, by S-nitrosylation of STIM1.
... Importantly, the vesicle release of neurotransmitters, neuropeptides and neurotrophin-3 has a common upstream mediator in Cadps2, which showed decreased cerebellar mRNA levels [151][152][153][154][155][156]. The balance between neurotrophin support and glutamate neurotoxicity is known to be critical also for the survival of Purkinje neurons [157][158][159][160]. ...
The autosomal recessive disorder Ataxia-Telangiectasia is caused by dysfunction of the stress response protein ATM. In the nucleus of proliferating cells, ATM senses DNA double-strand breaks and coordinates their repair. This role explains T-cell dysfunction and tumor risk. However, it remains unclear whether this function is relevant for postmitotic neurons and underlies the cerebellar atrophy, since ATM is cytoplasmic in postmitotic neurons. Here, we used ATM-null mice that survived early immune deficits by bone-marrow transplantation, and reached initial neurodegeneration stages at 12 months of age. Global cerebellar transcriptomics demonstrated ATM depletion to trigger upregulations in most neurotransmission and neuropeptide systems. Downregulated transcripts were found for the ATM interactome component Usp2, many non-coding RNAs, ataxia genes Itpr1, Grid2, immediate early genes and immunity factors. Allelic splice changes affected prominently neuropeptide machinery, e.g. Oprm1. Validation experiments with stressors were performed in human neuroblastoma cells, where ATM localized only to cytoplasm, similar to brain. Effect confirmation in SH-SY5Y cells occurred after ATM depletion and osmotic stress better than nutrient / oxidative stress, not after ATM kinase inhibition or DNA stressor bleomycin. Overall, we provide pioneer observations from a faithful A-T mouse model, which suggest general changes in synaptic and dense-core vesicle stress adaptation.
... Even though studies in cultured cerebellar neurons demonstrated the role of GCs in PC dendrite outgrowth (Baptista et al., 1994;Morrison and Mason, 1998;Hirai and Launey, 2000), GCs were originally considered to be inessential for PC dendrite development in vivo. This is because PC dendrite morphology was not altered when PF-PC synapses were globally impaired in transgenic mice expressing tetanus toxin (TeTx) in GCs (Kim et al., 2009) or in knockout mice lacking GluD2 (Kashiwabuchi et al., 1995;, type 1 metabotropic glutamate receptor (mGluR1; Kano et al., 1997), or Cbln1 (Hirai et al., 2005). ...
The well-organized cerebellar structures and neuronal networks are likely crucial for their functions in motor coordination, motor learning, cognition, and emotion. Such cerebellar structures and neuronal networks are formed during developmental periods through orchestrated mechanisms, which include not only cell-autonomous programs but also interactions between the same or different types of neurons. Cerebellar granule cells (GCs) are the most numerous neurons in the brain and are generated through intensive cell division of GC precursors (GCPs) during postnatal developmental periods. While GCs go through their own developmental processes of proliferation, differentiation, migration, and maturation, they also play a crucial role in cerebellar development. One of the best-characterized contributions is the enlargement and foliation of the cerebellum through massive proliferation of GCPs. In addition to this contribution, studies have shown that immature GCs and GCPs regulate multiple factors in the developing cerebellum, such as the development of other types of cerebellar neurons or the establishment of afferent innervations. These studies have often found impairments of cerebellar development in animals lacking expression of certain molecules in GCs, suggesting that the regulations are mediated by molecules that are secreted from or present in GCs. Given the growing recognition of GCs as regulators of cerebellar development, this review will summarize our current understanding of cerebellar development regulated by GCs and molecules in GCs, based on accumulated studies and recent findings, and will discuss their potential further contributions.
... As development proceeds (PN15, 30), the reduction of the BDNF protein in the PCs of mutant mice and its concomitant increase in the MF axon terminals become very clear. Since PCs receive BDNF from GCs [59,64], Npc1-related BDNF deficiency in PCs can be directly attributed to the reduced number of GCs; meanwhile, increased BDNF in MFs suggests an autocrine compensating mechanism for the recovery of BDNF signaling. Interestingly, unchanged levels of BDNF protein were detected in young adult mutant mice compared to wt mice. ...
Niemann-Pick type C1 (NPC1) disease is a lysosomal lipid storage disorder due to mutations in the NPC1 gene resulting in the accumulation of cholesterol within the endosomal/lysosomal compartments. The prominent feature of the disorder is the progressive Purkinje cell degeneration leading to ataxia.
In a mouse model of NPC1 disease, we have previously demonstrated that impaired Sonic hedgehog signaling causes defective proliferation of granule cells (GCs) and abnormal cerebellar morphogenesis. Studies conducted on cortical and hippocampal neurons indicate a functional interaction between Sonic hedgehog and brain-derived neurotrophic factor (BDNF) expression, leading us to hypothesize that BDNF signaling may be altered in Npc1 mutant mice, contributing to the onset of cerebellar alterations present in NPC1 disease before the appearance of signs of ataxia.
We characterized the expression/localization patterns of the BDNF and its receptor, tropomyosin-related kinase B (TrkB), in the early postnatal and young adult cerebellum of the Npc1nmf164 mutant mouse strain.
In Npc1nmf164 mice, our results show: (i) a reduced expression of cerebellar BDNF and pTrkB in the first two weeks postpartum, phases in which most GCs complete the proliferative/migrative program and begin differentiation; (ii) an altered subcellular localization of the pTrkB receptor in GCs, both in vivo and in vitro; (iii) reduced chemotactic response to BDNF in GCs cultured in vitro, associated with impaired internalization of the activated TrkB receptor; (iv) an overall increase in dendritic branching in mature GCs, resulting in impaired differentiation of the cerebellar glomeruli, the major synaptic complex between GCs and mossy fibers.
... Lärkfors et al. (1996) found that survival of PCs increases after in vitro treatment with BDNF. Additionally, Morrison and Mason (1998) found that BDNF improves PC survival in isolated cultures, but decreases when co-cultured with CGNs, indicating that the neurotrophic action is context-and activity-dependent. However, recent findings suggest that BDNF does not exert a survival effect on naïve PCs in vivo but promotes survival in damaged PCs (Rakotomamonjy and Goumari, 2019). ...
... References BDNF CGN survival Bulleit and Hsieh (2000), Kubo et al. (1995), Leeds et al. (2005), Lindholm et al. (1993), Nonomura et al. (1996), Ortega et al. (2010, Sanchez-Perez et al. (2005), Shimoke et al. (1997), Skaper et al. (1998), Tong and Perez-Polo (1998), Zirrgiebel et al. (1995), and Koshimizu et al. (2010) CGN migration Borghesani et al. (2002), Kokubo et al. (2009), andZhou et al. (2007) CGN neurite outgrowth Gao et al. (1995), Nonomura et al. (1996), and Tanaka et al. (2000) PC survival Lärkfors et al. (1996), Rakotomamonjy and Goumari (2019), and Morrison and Mason (1998) PC neurite outgrowth Schwartz et al. (1997), Shimada et al. (1998), and Yamashita et al. (2011) Circuit wiring Bosman et al. (2006), Carter et al. (2002), Minichiello (1996), Rico et al. (2002), Schwartz et al. (1997), Shinoda et al. Circuit wiring Lackey and Sillitoe (2020) Cerebellar foliation Karam et al. (2000) and Rogers et al. (1999) EGF CGN survival Abe et al. (1991, Morrison et al. (1988), Yamada et al. (1997), Gunn-Moore and Tavaré (1998) and Leutz and Schachner (1981) CGN migration Carrasco et al. (2003), and Martinez et al. (2011) CGN neurite development Abe et al. (1991, Morrison et al. (1988), and Yamada et al. (1997) NSC proliferation Okano-Uchida et al. (2013) and Leutz and Schachner (1981) GDNF CGN survival Subramaniam et al. (2008) PC survival Mount et al. (1995) PC neurite outgrowth Mount et al. (1995) MLI survival Sergaki and Ibáñez (2017) NGF CGN survival Legrand and Clos (1991), Muller et al. (1994), Khursigara et al. (2001), Kisiswa et al. (2018), and Vicario et al. (2015) PC CGN migration Neveu and Arenas (1996) PC survival Lärkfors et al. (1996) and Mount et al. (1998) PC neurite outgrowth Joo et al. (2014), Neveu and Arenas (1996), and Tepper et al. (2020) Circuit wiring Sadakata et al. (2014), Shinoda et al. (2019), and Sherrard and Bower (2002) (Continued) ...
The cerebellum is a multifunctional brain region that controls diverse motor and non-motor behaviors. As a result, impairments in the cerebellar architecture and circuitry lead to a vast array of neuropsychiatric and neurodevelopmental disorders. Neurotrophins and neurotrophic growth factors play essential roles in the development as well as maintenance of the central and peripheral nervous system which is crucial for normal brain function. Their timely expression throughout embryonic and postnatal stages is important for promoting growth and survival of both neurons and glial cells. During postnatal development, the cerebellum undergoes changes in its cellular organization, which is regulated by a variety of molecular factors, including neurotrophic factors. Studies have shown that these factors and their receptors promote proper formation of the cerebellar cytoarchitecture as well as maintenance of the cerebellar circuits. In this review, we will summarize what is known on the neurotrophic factors' role in cerebellar postnatal development and how their dysregulation assists in developing various neurological disorders. Understanding the expression patterns and signaling mechanisms of these factors and their receptors is crucial for elucidating their function within the cerebellum and for developing therapeutic strategies for cerebellar-related disorders.
... Both in vitro and in vivo studies have shown that hMSCs migrate to the site of lesion and release trophic factors, such as BDNF, GDNF, IGF-1, and VEGF, as well as neuroregulatory factors, including SEM74 and cadherin-2, which are implicated in the survival of Purkinje neurons and attenuation of local inflammation [16]. Among these, BDNF and GDNF are some of the most active neurotrophins supporting the viability of existing neurons, thus promoting the growth and differentiation of new neurons [56][57][58][59][60][61][62]. According to a previous report, hMSCs can directly produce BDNF and GDNF in the injured brain. ...
... Mice with targeted BDNF gene deletion display abnormal gait, increased granule cell death, and impaired Purkinje cell morphology, accompanied by a reduction in tropomyosin receptor kinase B activation, suggesting that BDNF directly targets both cell types in the cerebellum [59]. Moreover, BDNF also results in increased spine density in surviving Purkinje cells in vitro [60]. Notably, in the absence of BDNF, the secretome-induced axonal elongation effect is also lost [63]. ...
This study investigated the therapeutic effects of transplanting human mesenchymal stem cells (hMSCs) into wild-type mice that were intraperitoneally administered cytosine arabinoside (Ara-C) to develop cerebellar ataxia (CA) during the first three postnatal days. hMSCs were intrathecally injected into 10-week-old mice once or thrice at 4-week intervals. Compared to the nontreated mice, the hMSC-treated mice showed improved motor and balance coordination, as measured using the rotarod, open-field, and ataxic scoring assessments, and increased protein levels in Purkinje and cerebellar granule cells, as measured using calbindin and NeuN protein markers. Multiple hMSC injections preserved Ara-C-induced cerebellar neuronal loss and improved cerebellar weight. Furthermore, the hMSC implantation significantly elevated the levels of neurotrophic factors, including brain-derived and glial cell line-derived neurotrophic factors, and suppressed TNF-α-, IL-1β-, and iNOS-mediated proinflammatory responses. Collectively, our results demonstrate that hMSCs exhibit therapeutic potential for Ara-C-induced CA by protecting neurons through the stimulation of neurotrophic factors and inhibition of cerebellar inflammatory responses, which can improve motor behavior and alleviate ataxia-related neuropathology. In summary, this study suggests that hMSC administration, particularly multiple treatments, can effectively treat ataxia-related symptoms with cerebellar toxicity.
... Granule cells migrate from the EGL to internal granule layer (IGL) during development, creating parallel fibers that synapse onto Purkinje cells. This input is critical for Purkinje cell development and survival, as the absence of granule cells results in reduced Purkinje cell differentiation and increased Purkinje cell death [9]. Purkinje neurons are the sole output cells of the cerebellar cortex, sending their axons through the IGL and white matter to synapse onto the deep cerebellar nucleus (DCN). ...
... During the last trimester of pregnancy, the cerebellum became larger in size of overall structures with an increased surface area and folial complexity as described in human cerebellum [7,18,19] (Figure 1b). Granule cells influence structural and functional development and maturation of Purkinje cells [9], which occurs during late gestation in primates. Granule cells migrate from the external granule layer Brain Sci. ...
... During gestational development of the cerebellum, a key event is migration of granule cells from EGL to IGL, during which time they form synapses onto Purkinje cells [7]. Morphological and physiological development of Purkinje cells may be regulated by synaptic input from granule cells [9]. Therefore, we examined how synaptic inputs to Purkinje cells are changed throughout the later gestational development by recording spontaneous postsynaptic currents (sPSCs; Figure 3a). ...
Human cerebellar development occurs late in gestation and is hindered by preterm birth. The fetal development of Purkinje cells, the primary output cells of the cerebellar cortex, is crucial for the structure and function of the cerebellum. However, morphological and electrophysiological features in Purkinje cells at different gestational ages, and the effects of neonatal intensive care unit (NICU) experience on cerebellar development are unexplored. Utilizing the non-human primate baboon cerebellum, we investigated Purkinje cell development during the last trimester of pregnancy and the effect of NICU experience following premature birth on developmental features of Purkinje cells. Immunostaining and whole-cell patch clamp recordings of Purkinje cells in the baboon cerebellum at different gestational ages revealed that molecular layer width, driven by Purkinje dendrite extension, drastically increased and refinement of action potential waveform properties occurred throughout the last trimester of pregnancy. Preterm birth followed by NICU experience for 2 weeks impeded development of Purkinje cells, including action potential waveform properties, synaptic input, and dendrite extension compared with age-matched controls. In addition, these alterations impact Purkinje cell output, reducing the spontaneous firing frequency in deep cerebellar nucleus (DCN) neurons. Taken together, the primate cerebellum undergoes developmental refinements during late gestation, and NICU experience following extreme preterm birth influences morphological and physiological features in the cerebellum that can lead to functional deficits.
... This study also revealed that BDNF is necessary for granule cell axon growth. Furthermore, Morrison and Mason (1998) examined the influence of neurotrophins on the development of Purkinje cells using the granule-Purkinje cell co-culture technique. They found that purified Purkinje cells from the mouse cerebellum did not develop dendritic trees when cultured alone. ...
In therian mammals, the cerebellum is one of the late developing structures in the brain. Specifically, the proliferation of cerebellar granule cells occurs after birth, and even in humans, the generation of these cells continues during the first year of life. The main difference between marsupials and eutherians is that the majority of the brain structures in marsupials develop after birth. Herein, we report that in the newborn laboratory opossum (Monodelphis domestica), the cerebellar primordium is distinguishable in Nissl-stained sections. Additionally, bromodeoxyuridine birthdating experiments revealed that the first neurons form the deep cerebellar nuclei (DCN) and Purkinje cells, and are generated within postnatal days (P) 1 and 5. Three weeks after birth, progenitors of granule cells in the external germinal layer (EGL) proliferate, producing granule cells. These progenitor cells persist for a long time, approximately 5 months. Furthermore, to study the effects of neurotrophic tropomyosin receptor kinase C (TrkC) during cerebellar development, cells were obtained from P3 opossums and cultured for 8 days. We found that TrkC downregulation stimulates dendritic branching of Purkinje neurons, which was surprising. The number of dendritic branches was higher in Purkinje cells transfected with the shRNA TrkC plasmid. However, there was no morphological change in the number of dendritic branches of granule cells transfected with either control or shRNA TrkC plasmids. We suggest that inhibition of TrkC activity enables NT3 binding to the neurotrophic receptor p75NTR that promotes dendritic arborization of Purkinje cells. This effect of TrkC receptors on dendritic branching is cell type specific, which could be explained by the strong expression of TrkC in Purkinje cells but not in granule cells. The data indicate a new role for TrkC receptors in Monodelphis opossum.
... Granule cells influence structural and functional development and maturation of Purkinje cells (Morrison & Mason 1998), which occurs during late gestation in primates. Granule cells migrate from the external granule layer (EGL) to the internal granule layer (IGL) throughout gestation and early infancy, during which time they create parallel fibers that synapse onto Purkinje neurons (Volpe, 2009). ...
... Morphological and physiological development of Purkinje cells may be regulated by synaptic input from granule cells (Morrison & Mason, 1998). Therefore, we examined how synaptic inputs to Purkinje cells are changed throughout the later gestational development by recording spontaneous postsynaptic currents (sPSCs; Figure 3A). ...
Human cerebellar development occurs late in gestation and is hindered by preterm birth. The fetal development of Purkinje cells, the primary output cells of the cerebellar cortex, is crucial for the structure and function of the cerebellum. However, morphological and electrophysiological features in Purkinje cells at different gestational ages, and the effects of neonatal intensive care unit (NICU) experience on cerebellar development are unexplored. Utilizing non-human primate baboon cerebellum, we investigated Purkinje cell development during the last trimester of pregnancy and the effect of NICU experience following premature birth on developmental features of Purkinje cells. Immunostaining and whole-cell patch clamp recordings of Purkinje cells in the baboon cerebellum at different gestational ages revealed that molecular layer width, driven by Purkinje dendrite extension, drastically increased and refinement of action potential waveform properties occurred throughout the last trimester of pregnancy. Preterm birth followed by NICU experience for 2 weeks impeded development of Purkinje cells, including action potential waveform properties, synaptic input, and dendrite extension compared with age-matched controls. In addition, these alterations impact Purkinje cell output, reducing the spontaneous firing frequency in deep cerebellar nucleus (DCN) neurons. Taken together, primate cerebellum undergoes developmental refinements during late gestation, and NICU experience following preterm birth alters morphological and physiological features in the cerebellum that can lead to functional deficits.
Summary Statement
Baboon cerebellum undergoes developmental refinements during late gestation, and NICU experience following preterm birth impacts cellular development in the cerebellum that can lead to functional deficits.
... Ces résultats ont été confirmés par Carter et al. (2002). En effet chez les souris BDNF-/-, l'arborisation dendritique des cellules de Purkinje était Mason, 1998 ;Shimada et al., 1998). Par ailleurs, une délétion du gène codant pour le récepteur TrkB, induit une réduction d'environ 20 % de l'arborisation dendritique des cellules de Purkinje (Minichiello et Klein, 1996 ;Rico et al., 2002 ;Bosman et al., 2006) sans modification du nombre de cellules de Purkinje et de cellules à grains (Minichiello et Klein, 1996 ;Rico et al., 2002). ...
... Cependant, dans cette étude, le nombre de ces synapses était réduit. Ce résultat est confirmé par d'autres études qui ont montré que l'absence de BDNF est délétère pour la morphologie et le nombre d'épines dendritiques des cellules de Purkinje (Morrison et Mason, 1998 ;Shimada et al., 1998). Shimada et al., (1998) ont montré que des cellules de Purkinje mises en culture en présence de BDNF présentaient une densité plus importante d'épines dendritiques avec une répartition similaire des épines entre les dendrites proximales et les dendrites distales. ...
... Dans notre étude, l'administration de corticostérone de J8 à J15 PN induit une diminution très importante de l'expression du gène codant pour GluRδ2 suggérant ainsi une perturbation de la synaptogenèse. A noter également que cette étape du développement implique d'autres facteurs tels que la CRH ou le BDNF qui modulent la densité des épines dendritiques des cellules de Purkinje (Gounko et al., 2013 ;Morrison et Mason, 1998 ;Shimada et al., 1998). Or aucune modification d'expression des gènes codant pour ces deux neuromodulateurs n'a été observée dans notre étude. ...
Plusieurs études ont montré que le cervelet et l’hippocampe, étaient vulnérables à toutes modifications environnementales telles qu’une exposition à un stress ou un taux supraphysiologique de glucocorticoïdes. Cette vulnérabilité s’observe sur l’organisation cellulaire et moléculaire de ces deux structures et se traduit par des désordres fonctionnels sous forme de déficits moteurs, cognitifs ou émotionnels. Les effets d’un stress chronique sur la mise en place des effecteurs cellulaires de l’hippocampe et du cervelet sont bien rapportés dans la littérature lorsque l’animal subi un stress chronique durant la période embryonnaire. Cependant la période postnatale et plus particulièrement les deux dernières semaines correspondant, pour le cervelet, à la mise en place de la couche granulaire interne et à l’établissement des contacts synaptiques entre les cellules de Purkinje et ses afférences reste peu étudié. Ce travail a donc pour objectif d’étudier cette période cruciale pour la maturation fonctionnelle du cervelet afin de répondre dans un premier temps à deux questions principales : 1) La corticostérone administrée chroniquement chez le souriceau durant cette période pourrait-elle induire un effet délétère sur le développement postnatal du cervelet ? 2) Les glucocorticoïdes sont-ils capables de modifier l’expression de certains facteurs neurotrophiques impliqués dans la mise en place et l’organisation des différents types cellulaires retrouvés au sein du cervelet et in fine avoir un impact à long terme sur la fonctionnalité du cervelet ? Pour répondre à ces hypothèses, chaque souriceau a reçu durant 21 jours consécutifs une injection sous-cutanée de corticostérone (20 mg/kg) ou de diméthylsulfoxyde (groupe contrôle) de J8 à J29 PN. Les résultats ont montré qu’une administration chronique de corticostérone de J8 à J29 postnatal avait des effets sur le développement du cervelet et de l’hippocampe qui s’exprimaient au niveau de l’organisation cellulaire des structures et au niveau moléculaire par le biais de certains facteurs impliqués dans l’architectonie cellulaire et tissulaire (modification d’expression des gènes codant pour CRH-R1, CRH-R2, GR et GluRδ2 à J15). Ces effets s’inscrivent à long terme : 1) des modifications morphométriques telles qu’une augmentation d’épaisseur des couches granulaires et moléculaire de Crus II et une diminution d’épaisseur de la couche granulaire de Simplex ; 2) des changements d’activité métabolique régionale observée entre autres dans le cervelet, l’hippocampe, l’amygdale et le noyau vestibulaire latéral et 3) des variations du phénotype sensori-moteur mises en évidence dans l’actimètre, le rotarod et le test de la piscine de Morris, ont été observés à l’âge adulte. Enfin, l’administration chronique de corticostérone équivalente à des situations de stress durant l’enfance a modifié la réponse au stress à l’âge adulte comme l’ont montré les différents dosages des hormones du stress effectués dans l’hypothalamus et l’hippocampe. Cette étude a permis de démontrer qu’une exposition chronique à la corticostérone durant la période postnatale avait des effets immédiats mais aussi un impact à long terme sur la structure et la fonctionnalité du cervelet.
