Reduced Cerebellar BDNF Availability Affects Postnatal Differentiation and Maturation of Granule Cells in a Mouse Model of Cholesterol Dyshomeostasis.

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 2 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.

Positive Touch Deprivation during the COVID-19 Pandemic: Effects on Anxiety, Stress, and Depression among Italian General Population.

Physical distancing due to the COVID-19 Pandemic has limited the opportunities for family members, friends, and significant others to show physical affection (i.e., hugs, kisses, caresses, holding hands) during social interactions. The present study investigated the effects of positive touch and psychological distress in 991 Italian participants (Mage = 34.43, SD = 14.27). Results showed the frequency of hugs with the cohabiting partner significantly decreased the symptoms of depression (ß = -1.187, p = 0.018, eß = 0.30, 95% CI = 0.11-0.82), whereas the frequency of caresses with cohabiting relatives predicted the symptoms of anxiety (ß = 0.575, p = 0.034, eß = 1.78, 95% CI = 1.04-3.03). The frequency of hugs (ß = -0.609, p = 0.049, eß = 0.54, 95% CI = 0.30-1.00), and kisses (ß = 0.663, p = 0.045, eß = 1.94, 95% CI = 1.01-3.71) with non-cohabiting relatives predicted the symptoms of anxiety (χ2 = 1.35, df = 5, p = 0.93). These results suggest the importance of positive touch on psychological well-being in the social context.

Sex differences in antioxidant defence and the regulation of redox homeostasis in physiology and pathology.

Reactive oxygen species (ROS) is a term that defines a group of unstable compounds derived from exogenous sources or endogenous metabolism. Under physiological conditions, low levels of ROS play a key role in the regulation of signal transduction- or transcription-mediated cellular responses. In contrast, excessive and uncontrolled loading of ROS results in a pathological state known as oxidative stress (OS), a leading contributor to aging and a pivotal factor for the onset and progression of many disorders. Evolution has endowed cells with an antioxidant system involved in stabilizing ROS levels to a specific threshold, maintaining ROS-induced signalling function and limiting negative side effects. In mammals, a great deal of evidence indicates that females defence against ROS is more proficient than males, determining a longer lifespan and lower incidence of most chronic diseases. In this review, we will summarize the most recent sex-related differences in the regulation of redox homeostasis. We will highlight the peculiar aspects of the antioxidant defence in sex-biased diseases whose onset or progression is driven by OS, and we will discuss the molecular, genetic, and evolutionary determinants of female proficiency to cope with ROS.

The Antifungal Antibiotic Filipin as a Diagnostic Tool of Cholesterol Alterations in Lysosomal Storage Diseases and Neurodegenerative Disorders.

Cholesterol is the most considerable member of a family of polycyclic compounds understood as sterols, and represents an amphipathic molecule, such as phospholipids, with the polar hydroxyl group located in position 3 and the rest of the molecule is completely hydrophobic. In cells, it is usually present as free, unesterified cholesterol, or as esterified cholesterol, in which the hydroxyl group binds to a carboxylic acid and thus generates an apolar molecule. Filipin is a naturally fluorescent antibiotic that exerts a primary antifungal effect with low antibacterial activity, interfering with the sterol stabilization of the phospholipid layers and favoring membrane leakage. This polyene macrolide antibiotic does not bind to esterified sterols, but only to non-esterified cholesterol, and it is commonly used as a marker to label and quantify free cholesterol in cells and tissues. Several lines of evidence have indicated that filipin staining could be a good diagnostic tool for the cholesterol alterations present in neurodegenerative (e.g., Alzheimer's Disease and Huntington Disease) and lysosomal storage diseases (e.g., Niemann Pick type C Disease and GM1 gangliosidosis). Here, we have discussed the uses and applications of this fluorescent molecule in lipid storage diseases and neurodegenerative disorders, exploring not only the diagnostic strength of filipin staining, but also its limitations, which over the years have led to the development of new diagnostic tools to combine with filipin approach.

The Cerebellum in Niemann-Pick C1 Disease: Mouse Versus Man.

Selective neuronal vulnerability is common to most degenerative disorders, including Niemann-Pick C (NPC), a rare genetic disease with altered intracellular trafficking of cholesterol. Purkinje cell dysfunction and loss are responsible for cerebellar ataxia, which is among the prevailing neurological signs of the NPC disease. In this review, we focus on some questions that are still unresolved. First, we frame the cerebellar vulnerability in the context of the extended postnatal time length by which the development of this structure is completed in mammals. In line with this thought, the much later development of cerebellar symptoms in humans is due to the later development and/or maturation of the cerebellum. Hence, the occurrence of developmental events under a protracted condition of defective intracellular cholesterol mobilization hits the functional maturation of the various cell types generating the ground of increased vulnerability. This is particularly consistent with the high cholesterol demand required for cell proliferation, migration, differentiation, and synapse formation/remodeling. Other major questions we address are why the progression of Purkinje cells loss is always from the anterior to the posterior lobes and why cerebellar defects persist in the mouse model even when genetic manipulations can lead to nearly normal survival.

The appearance of phagocytic microglia in the postnatal brain of Niemann Pick type C mice is developmentally regulated and underscores shortfalls in fine odor discrimination.

The loss of NPC1 or NPC2 function results in cholesterol and sphingolipid dyshomeostasis that impairs developmental trajectories, predisposing the postnatal brain to the appearance of pathological signs, including progressive and stereotyped Purkinje cell loss and microgliosis. Despite increasing evidence reporting the activation of pro-inflammatory microglia as a cardinal event of NPC1 disease progression at symptomatic stages both in patients and preclinical models, how microglia cells respond to altered neurodevelopmental dynamics remains not completely understood. To gain an insight on this issue, we have characterized patterns of microglia activation in the early postnatal cerebellum and young adult olfactory bulb of the hypomorphic Npc1nmf164 mouse model. Previous evidence has shown that both these areas display a number of anomalies affecting neuron and glial cell proliferation and differentiation, which largely anticipate cellular changes and clinical signs, raising our interest on how microglia interplay to these changes. Even so, to separate the contribution of cues provided by the dysfunctional microenvironment we have also studied microglia isolated from mice of increasing ages and cultured in vitro for 1 week. Our findings show that microglia of both cerebellum and olfactory bulb of Npc1nmf164 mice adopt an activated phenotype, characterized by increased cell proliferation, enlarged soma size and de-ramified processes, as well as a robust phagocytic activity, in a time- and space-specific manner. Enhanced phagocytosis associates with a profound remodeling of gene expression signatures towards gene products involved in chemotaxis, cell recognition and engulfment, including Cd68 and Trem2. These early changes in microglia morphology and activities are induced by region-specific developmental anomalies that likely anticipate alterations in neuronal connectivity. As a proof of concept, we show that microglia activation within the granule cell layer and glomerular layer of the olfactory bulb of Npc1nmf164 mice is associated with shortfalls in fine odor discrimination.

Antimicrobial Peptides (AMPs) in the Pathogenesis of Alzheimer's Disease: Implications for Diagnosis and Treatment.

Alzheimer's disease (AD) represents the most frequent type of dementia in elderly people. There are two major forms of the disease: sporadic (SAD)-whose causes are not completely understood-and familial (FAD)-with clear autosomal dominant inheritance. The two main hallmarks of AD are extracellular deposits of amyloid-beta (Aß) peptide and intracellular deposits of the hyperphosphorylated form of the tau protein (P-tau). An ever-growing body of research supports the infectious hypothesis of sporadic forms of AD. Indeed, it has been documented that some pathogens, such as herpesviruses and certain bacterial species, are commonly present in AD patients, prompting recent clinical research to focus on the characterization of antimicrobial peptides (AMPs) in this pathology. The literature also demonstrates that Aß can be considered itself as an AMP; thus, representing a type of innate immune defense peptide that protects the host against a variety of pathogens. Beyond Aß, other proteins with antimicrobial activity, such as lactoferrin, defensins, cystatins, thymosin ß4, LL37, histatin 1, and statherin have been shown to be involved in AD. Here, we summarized and discussed these findings and explored the diagnostic and therapeutic potential of AMPs in AD.

Pleiotropic effects of BDNF on the cerebellum and hippocampus: Implications for neurodevelopmental disorders.

Brain-derived neurotrophic factor (BDNF) is one of the most studied neurotrophins in the mammalian brain, essential not only to the development of the central nervous system but also to synaptic plasticity. BDNF is present in various brain areas, but highest levels of expression are seen in the cerebellum and hippocampus. After birth, BDNF acts in the cerebellum as a mitogenic and chemotactic factor, stimulating the cerebellar granule cell precursors to proliferate, migrate and maturate, while in the hippocampus BDNF plays a fundamental role in synaptic transmission and plasticity, representing a key regulator for the long-term potentiation, learning and memory. Furthermore, the expression of BDNF is highly regulated and changes of its expression are associated with both physiological and pathological conditions. The purpose of this review is to provide an overview of the current state of knowledge on the BDNF biology and its neurotrophic role in the proper development and functioning of neurons and synapses in two important brain areas of postnatal neurogenesis, the cerebellum and hippocampus. Dysregulation of BDNF expression and signaling, resulting in alterations in neuronal maturation and plasticity in both systems, is a common hallmark of several neurodevelopmental diseases, such as autism spectrum disorder, suggesting that neuronal malfunction present in these disorders is the result of excessive or reduced of BDNF support. We believe that the more the relevance of the pathophysiological actions of BDNF, and its downstream signals, in early postnatal development will be highlighted, the more likely it is that new neuroprotective therapeutic strategies will be identified in the treatment of various neurodevelopmental disorders.

Sex moderates the association between the COMT Val158Met single-nucleotide polymorphism and disorderliness facet of novelty seeking.

Previous studies have shown inconsistent results regarding the effect of the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene on personality and cognition. Here, nonclinical Caucasian university students of Italian origin were administered the Temperament and Character Inventory-Revised, Tellegen Absorption Scale, Differential Attentional Processes Inventory, and Waterloo-Stanford Group Scale of Hypnotic Susceptibility. We found that the COMT Val158Met polymorphism was significantly associated with the disorderliness facet of novelty seeking (NS4) and that sex was a moderator of this association. Females with the Met/Met genotype showed higher NS4 scores compared to those with the Val/Met and Val/Val genotypes. No significant genotype effect was found for males. Additionally, we failed to find a significant effect of the COMT gene on attention and hypnotic suggestibility measures. These results provide further evidence for a sex-specific influence on the gene-behaviour associations.

Decreased neural stem cell proliferation and olfaction in mouse models of Niemann-Pick C1 disease and the response to hydroxypropyl-ß-cyclodextrin.

The Npc1nih/nih-null model and the Npc1nmf164/nmf164 hypomorph models of Niemann-Pick C1 (NPC1) disease show defects in olfaction. We have tested the effects of the life-prolonging treatment hydroxypropyl-beta-cyclodextrin (HPBCD) on olfaction and neural stem cell numbers when delivered either systemically or by nasal inhalation. Using the paradigm of finding a hidden cube of food after overnight food deprivation, Npc1nih/nih homozygous mice showed a highly significant delay in finding the food compared with wild-type mice. Npc1nmf164/nmf164 homozygous mice showed an early loss of olfaction which was mildly corrected by somatic delivery of HPBCD which also increased the number of neural stem cells in the mutant but did not change the number in wild-type mice. In contrast, nasal delivery of this drug, at 1/5 the dosage used for somatic delivery, to Npc1nmf164/nmf164 mutant mice delayed loss of olfaction but the control of nasal delivered saline did so as well. The nasal delivery of HPBCD to wild-type mice caused loss of olfaction but nasal delivery of saline did not. Neural stem cell counts were not improved by nasal therapy with HPBCD. We credit the delay in olfaction found with the treatment, a delay which was also found for time of death, to a large amount of stimulation the mice received with handling during the nasal delivery.

The endocannabinoid system is affected by cholesterol dyshomeostasis: Insights from a murine model of Niemann Pick type C disease.

The dyshomeostasis of intracellular cholesterol trafficking is typical of the Niemann-Pick type C (NPC) disease, a fatal inherited lysosomal storage disorder presenting with progressive neurodegeneration and visceral organ involvement. In light of the well-established relevance of cholesterol in regulating the endocannabinoid (eCB) system expression and activity, this study was aimed at elucidating whether NPC disease-related cholesterol dyshomeostasis affects the functional status of the brain eCB system. To this end, we exploited a murine model of NPC deficiency for determining changes in the expression and activity of the major molecular components of the eCB signaling, including cannabinoid type-1 and type-2 (CB1 and CB2) receptors, their ligands, N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), along with their main synthesizing/inactivating enzymes. We found a robust alteration of distinct components of the eCB system in various brain regions, including the cortex, hippocampus, striatum and cerebellum, of Npc1-deficient compared to wild-type pre-symptomatic mice. Changes of the eCB component expression and activity differ from one brain structure to another, although 2-AG and AEA are consistently found to decrease and increase in each structure, respectively. The thorough biochemical characterization of the eCB system was accompanied by a behavioral characterization of Npc1-deficient mice using a number of paradigms evaluating anxiety, locomotor activity, spatial learning/memory abilities, and coping response to stressful experience. Our findings provide the first description of an early and region-specific alteration of the brain eCB system in NPC and suggest that defective eCB signaling could contribute at producing and/or worsening the neurological symptoms of this disorder.

Anomalies in Dopamine Transporter Expression and Primary Cilium Distribution in the Dorsal Striatum of a Mouse Model of Niemann-Pick C1 Disease.

The Niemann-Pick type C1 (NPC1) is a rare genetic disease characterized by the accumulation of endocytosed cholesterol and other lipids in the endosome/lysosome compartments. In the brain, the accumulation/mislocalization of unesterified cholesterol, gangliosides and sphingolipids is responsible for the appearance of neuropathological hallmarks, and progressive neurological decline in patients. The imbalance of unesterified cholesterol and other lipids, including GM2 and GM3 gangliosides, alters a number of signaling mechanisms impacting on the overall homeostasis of neurons. In particular, lipid depletion experiments have shown that lipid rafts regulate the cell surface expression of dopamine transporter (DAT) and modulate its activity. Dysregulated dopamine transporter's function results in imbalanced dopamine levels at synapses and severely affects dopamine-induced locomotor responses and dopamine receptor-mediated synaptic signaling. Recent studies begin to correlate dopaminergic stimulation with the length and function of the primary cilium, a non-motile organelle that coordinates numerous signaling pathways. In particular, the absence of dopaminergic D2 receptor stimulation induces the elongation of dorso-striatal neuron's primary cilia. This study has used a mouse model of the NPC1 disease to correlate cholesterol dyshomeostasis with dorso-striatal anomalies in terms of DAT expression and primary cilium (PC) length and morphology. We found that juvenile Npc1nmf164 mice display a reduction of dorso-striatal DAT expression, with associated alterations of PC number, length-frequency distribution, and tortuosity.

The interplay between TGF-ß-stimulated TSC22 domain family proteins regulates cell-cycle dynamics in medulloblastoma cells.

Proteins belonging to the TGFß-stimulated clone 22 domain (TSC22D) family display a repertoire of activities, regulating cell proliferation and differentiation. The tumor suppressor activity of the first identified member of the family, TSC22D1 (formerly named TSC-22), has been extensively studied, but afterward a longer isoform encoded by the same gene turned out to play an opposite role. We have previously characterized the role of TSC22D1 and TSC22D4 in cell differentiation using granule neurons (GNs) isolated from the mouse cerebellum. However, the possibility to study the role of these factors in cell proliferation was limited by the fact that GNs readily exit from the cell-cycle and differentiate upon isolation and in vitro culture. To overcome this limitation, we have now exploited DAOY medulloblastoma cells, which are ontogenetically similar to cerebellar GNs and can be efficiently transfected with interfering RNA for gene knockdown purposes. Our findings indicate that TSC22D4-TSC22D1 short isoform heterodimers are involved in the escape from cell proliferation and exit from the cell-cycle, whereas, the TSC22D1 long isoform is required for cell proliferation, acting independently from TSC22D4. We also show that the silencing of specific expression of TSC22D4 or TSC22D1 isoforms affects the cell-cycle progression. These findings add a novel insight on the function of TSC22D proteins, with particular reference to the tumor suppressor activity of the TSC22D1 short isoform, which is re-framed within the context of a functional interplay with TSC22D4 and the mutually exclusive expression with the TSC22D1 long isoform.

Stress-Induced Reduction of Dorsal Striatal D2 Dopamine Receptors Prevents Retention of a Newly Acquired Adaptive Coping Strategy.

The inability to learn an adaptive coping strategy in a novel stressful condition leads to dysfunctional stress coping, a marker of mental disturbances. This study tested the involvement of dorsal striatal dopamine receptors in the dysfunctional coping with the Forced Swim test fostered by a previous experience of reduced food availability. Adult male mice were submitted to a temporary (12 days) reduction of food availability [food-restricted (FR)] or continuously free-fed (FF). Different groups of FF and FR mice were used to evaluate: (1) dorsal striatal mRNA levels of the two isoforms of the dopamine D2 receptor (D2S, D2L). (2) Forced Swim-induced c-fos expression in the dorsal striatum; (3) acquisition and 24 h retention of passive coping with Forced Swim. Additional groups of FF mice were tested for 24 h retention of passive coping acquired during a first experience with Forced Swim immediately followed by intra-striatal infusion of vehicle or two doses of the dopamine D2/D3 receptors antagonist sulpiride or the D1/D5 receptors antagonist SCH23390. Previous restricted feeding selectively reduced mRNA levels of both D2 isoforms and abolished Forced Swim-induced c-fos expression in the left Dorsolateral Striatum and selectively prevented 24 h retention of the coping strategy acquired in a first experience of Forced Swim. Finally, temporary blockade of left Dorsolateral Striatum D2/D3 receptors immediately following the first Forced Swim experience selectively reproduced the behavioral effect of restricted feeding in FF mice. In conclusion, the present results demonstrate that mice previously exposed to a temporary reduction of food availability show low striatal D2 receptors, a known marker of addiction-associated aberrant neuroplasticity, as well as liability to relapse into maladaptive stress coping strategies. Moreover, they offer strong support to a causal relationship between reduction of D2 receptors in the left Dorsolateral Striatum and impaired consolidation of newly acquired adaptive coping.

A Proteomic Approach to Study the Effect of Thiotaurine on Human Neutrophil Activation.

Thiotaurine, a thiosulfonate related to taurine and hypotaurine, is formed by a metabolic process from cystine and generated by a transulfuration reaction between hypotaurine and thiocysteine. Thiotaurine can produce hydrogen sulfide (H2S) from its sulfane sulfur moiety. H2S is a gaseous signaling molecule which can have regulatory roles in inflammatory process. In addition, sulfane sulfur displays the capacity to reversibly bind to other sulfur atoms. Thiotaurine inhibits PMA-induced activation of human neutrophils, and hinders neutrophil spontaneous apoptosis. Here, we present the results of a proteomic approach to study the possible effects of thiotaurine at protein expression level. Proteome analysis of human neutrophils has been performed comparing protein extracts of resting or PMA-activated neutrophils in presence or in absence of thiotaurine. In particular, PMA-stimulated neutrophils showed high level of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression compared to the level of the same glycolytic enzyme in the resting neutrophils. Conversely, decreased expression of GAPDH has been observed when human neutrophils were incubated with 1 mM thiotaurine before activation with PMA. This result, confirmed by Western blot analysis, suggests again that thiotaurine shows a bioactive role in the mechanisms underlying the inflammatory process, influencing the energy metabolism of activated leukocytes and raises the possibility that thiotaurine, acting as a sulfur donor, could modulate neutrophil activation via persulfidation of target proteins, such as GAPDH.

Shortened primary cilium length and dysregulated Sonic hedgehog signaling in Niemann-Pick C1 disease.

The Niemann-Pick type C1 (NPC1) disease is a neurodegenerative lysosomal storage disorder due to mutations in the NPC1 gene, encoding a transmembrane protein related to the Sonic hedgehog (Shh) receptor, Patched, and involved in intracellular trafficking of cholesterol. We have recently found that the proliferation of cerebellar granule neuron precursors is significantly reduced in Npc1-/- mice due to the downregulation of Shh expression. This finding prompted us to analyze the formation of the primary cilium, a non-motile organelle that is specialized for Shh signal transduction and responsible, when defective, for several human genetic disorders. In this study, we show that the expression and subcellular localization of Shh effectors and ciliary proteins are severely disturbed in Npc1-deficient mice. The dysregulation of Shh signaling is associated with a shortening of the primary cilium length and with a reduction of the fraction of ciliated cells in Npc1-deficient mouse brains and the human fibroblasts of NPC1 patients. These defects are prevented by treatment with 2-hydroxypropyl-ß-cyclodextrin, a promising therapy currently under clinical investigation. Our findings indicate that defective Shh signaling is responsible for abnormal morphogenesis of the cerebellum of Npc1-deficient mice and show, for the first time, that the formation of the primary cilium is altered in NPC1 disease.

Sexually Dimorphic Expression of Reelin in the Brain of a Mouse Model of Alzheimer Disease.

Recent evidence highlights the protective role of reelin against amyloid ß (Aß)-induced synaptic dysfunction and cognitive impairment in Alzheimer disease (AD). In this study, exploiting TgCRND8 mice that overexpress a mutant form of amyloid ß precursor protein (AßPP) and display an early onset of AD neuropathological signs, we addressed the question whether changes of reelin expression eventually precede the appearance of Aß-plaques in a sex-dependent manner. We show that sex-associated and brain region-specific differences in reelin expression appear long before Aß-plaque formation. However, in spite of a downregulation of reelin expression compared to males, TgCRND8 females display fewer Aß-plaques, suggesting that additional factors, other than sex and reelin level, influence amyloidosis in this mouse model.

Developmental delay in motor skill acquisition in Niemann-Pick C1 mice reveals abnormal cerebellar morphogenesis.

Niemann-Pick type C1 (NPC1) disease is a lysosomal storage disorder caused by defective intracellular trafficking of exogenous cholesterol. Purkinje cell (PC) degeneration is the main sign of cerebellar dysfunction in both NPC1 patients and animal models. It has been recently shown that a significant decrease in Sonic hedgehog (Shh) expression reduces the proliferative potential of granule neuron precursors in the developing cerebellum of Npc1 (-/-) mice. Pursuing the hypothesis that this developmental defect translates into functional impairments, we have assayed Npc1-deficient pups belonging to the milder mutant mouse strain Npc1 (nmf164) for sensorimotor development from postnatal day (PN) 3 to PN21. Npc1 (nmf164) / Npc1 (nmf164) pups displayed a 2.5-day delay in the acquisition of complex motor abilities compared to wild-type (wt) littermates, in agreement with the significant disorganization of cerebellar cortex cytoarchitecture observed between PN11 and PN15. Compared to wt, Npc1 (nmf164) homozygous mice exhibited a poorer morphological differentiation of Bergmann glia (BG), as indicated by thicker radial shafts and less elaborate reticular pattern of lateral processes. Also BG functional development was defective, as indicated by the significant reduction in GLAST and Glutamine synthetase expression. A reduced VGluT2 and GAD65 expression also indicated an overall derangement of the glutamatergic/GABAergic stimulation that PCs receive by climbing/parallel fibers and basket/stellate cells, respectively. Lastly, Npc1-deficiency also affected oligodendrocyte differentiation as indicated by the strong reduction of myelin basic protein. Two sequential 2-hydroxypropyl-ß-cyclodextrin administrations at PN4 and PN7 counteract these defects, partially preventing functional impairment of BG and fully restoring the normal patterns of glutamatergic/GABAergic stimulation to PCs.These findings indicate that in Npc1 (nmf164) homozygous mice the derangement of synaptic connectivity and dysmyelination during cerebellar morphogenesis largely anticipate motor deficits that are typically observed during adulthood.

Visual evoked potentials of Niemann-Pick type C1 mice reveal an impairment of the visual pathway that is rescued by 2-hydroxypropyl-ß-cyclodextrin.

BACKGROUND: The lysosomal storage disorder, Niemann Pick type C1 (NPC1), presents a variable phenotype including neurovisceral and neurological symptoms. 2-Hydroxypropyl-ß-cyclodextrin (HPßCD)-based therapies are presently the most promising route of intervention. While severe cerebellar dysfunction remains the main disabling feature of NPC1, sensory functions including auditory and olfactory ones are also affected. Morphological and functional anomalies of Npc1 (-/-) mouse retina have also been observed, although the functional integrity of the visual pathway from retina to visual cortex is still unsettled. We have addressed this issue by characterizing the visual evoked potential (VEP) response of Npc1 (-/-) mice and determining if/how HPßCD administration influences the VEPs of both Npc1 (-/-) and Npc1 (+/+) mice. METHODS: VEP elicited by a brief visual stimulus were recorded from the scalp overlying the visual cortex of adult (PN, postnatal days 60, 75, 85 and 100) Npc1 (+/+) and Npc1 (-/-) mice that had received repeated injections of either HPßCD or plain vehicle. The first injection was given at PN4 and was followed by a second one at PN7 and thereafter by weekly injections up to PN49. Cholesterol accumulation and myelin loss were finally assessed by filipin staining and myelin basic protein immunohistochemistry, respectively. RESULTS AND DISCUSSION: We have found that the transmission of visual signals from retina to visual cortex is negatively influenced by the loss of Npc1 function. In fact, the VEP response of Npc1 (-/-) mice displayed a highly significant increase in the latency compared to that of Npc1 (+/+) mice. HPßCD administration fully rescued this defect and counteracted the cholesterol accumulation in retinal ganglion cells and dorsal lateral geniculate nucleus neurons, as well as the myelin loss in optic nerve fibers and axons projecting to the visual cortex observed in of Npc1 (-/-) mice. By contrast, HPßCD administration had no effect on the VEP response of Npc1 (+/+) mice, further strengthening the treatment efficacy. CONCLUSIONS: This study pinpoints the analysis of VEP response as a potentially accurate and non-invasive approach to assess neural activity and visual information processing in NPC1 patients, as well as for monitoring the progression of the disease and assessing the efficacy of potential therapies.