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Cell Reports Oct 2018Despite a prevalence exceeding 1%, mechanisms underlying autism spectrum disorders (ASDs) are poorly understood, and targeted therapies and guiding parameters are...
Despite a prevalence exceeding 1%, mechanisms underlying autism spectrum disorders (ASDs) are poorly understood, and targeted therapies and guiding parameters are urgently needed. We recently demonstrated that cerebellar dysfunction is sufficient to generate autistic-like behaviors in a mouse model of tuberous sclerosis complex (TSC). Here, using the mechanistic target of rapamycin (mTOR)-specific inhibitor rapamycin, we define distinct sensitive periods for treatment of autistic-like behaviors with sensitive periods extending into adulthood for social behaviors. We identify cellular and electrophysiological parameters that may contribute to behavioral rescue, with rescue of Purkinje cell survival and excitability corresponding to social behavioral rescue. In addition, using anatomic and diffusion-based MRI, we identify structural changes in cerebellar domains implicated in ASD that correlate with sensitive periods of specific autism-like behaviors. These findings thus not only define treatment parameters into adulthood, but also support a mechanistic basis for the targeted rescue of autism-related behaviors.
Topics: Animals; Autistic Disorder; Behavior, Animal; Cells, Cultured; Cerebellum; Immunosuppressive Agents; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Purkinje Cells; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 1 Protein
PubMed: 30304677
DOI: 10.1016/j.celrep.2018.09.039 -
Translational Psychiatry Jul 2014The p75 neurotrophin receptor (p75NTR) is normally expressed in cerebellar Purkinje cells throughout the lifespan. Children with autism spectrum behavior exhibit...
The p75 neurotrophin receptor (p75NTR) is normally expressed in cerebellar Purkinje cells throughout the lifespan. Children with autism spectrum behavior exhibit apparent cerebellar Purkinje cell loss. Cerebellar transcriptome changes seen in the murine prenatal valproate exposure model of autism include all of the proteins known to constitute the p75NTR interactome. p75NTR is a modulator of cytoplasmic and mitochondrial redox potential, and others have suggested that aberrant response to oxidant stress has a major role in the pathogenesis of autism. We have created Purkinje cell-selective p75NTR knockout mice that are the progeny of hemizygous Cre-Purkinje cell protein 2 C57Bl mice and p75NTR floxed C57Bl mice. These Cre-loxP mice exhibit complete knockout of p75NTR in ~50% of the cerebellar Purkinje cells. Relative to Cre-only mice and wild-type C57Bl mice, this results in a behavioral phenotype characterized by less allogrooming of (P<0.05; one-way analysis of variance) and socialization or fighting with (each P<0.05) other mice; less (1.2-fold) non-ambulatory exploration of their environment than wild-type (P<0.01) or Cre only (P<0.01) mice; and almost twofold more stereotyped jumping behavior than wild-type (P<0.05) or Cre (P<0.02) mice of the same strain. Wild-type mice have more complex dendritic arborization than Cre-loxP mice, with more neurites per unit area (P<0.025, Student's t-test), more perpendicular branches per unit area (P<0.025) and more short branches/long neurite (P<0.0005). Aberrant developmental regulation of expression of p75NTR in cerebellar Purkinje cells may contribute to the pathogenesis of autism.
Topics: Agonistic Behavior; Animals; Autistic Disorder; Disease Models, Animal; Gene Expression; Mice; Mice, Inbred C57BL; Mice, Knockout; Phenotype; Purkinje Cells; Receptors, Nerve Growth Factor; Socialization; Stereotyped Behavior; Transcriptome
PubMed: 25072321
DOI: 10.1038/tp.2014.55 -
Neurobiology of Learning and Memory Dec 2019There is a long history of research documenting plasticity in the cerebellum as well as the role of the cerebellum in learning and memory. Recordings in slices of... (Review)
Review
There is a long history of research documenting plasticity in the cerebellum as well as the role of the cerebellum in learning and memory. Recordings in slices of cerebellum have provided evidence of long-term depression and long-term potentiation at several excitatory and inhibitory synapses. Lesions and recordings show the cerebellum is crucial for eyeblink conditioning and it appears changes in both synaptic and membrane plasticity are involved. In addition to its role in fine motor control, there is growing consensus that the cerebellum is crucial for perceptual, cognitive, and emotional functions. In the current review, we explore the evidence that eyeblink conditioning results in significant changes in intrinsic membrane excitability as well as synaptic plasticity in Purkinje cells of the cerebellar cortex in rabbits and changes in intrinsic membrane excitability in principal neurons of the deep cerebellar nuclei in rats.
Topics: Animals; Cerebellum; Conditioning, Eyelid; Neuronal Plasticity; Neurons; Purkinje Cells; Rabbits
PubMed: 31542329
DOI: 10.1016/j.nlm.2019.107094 -
Acta Neuropathologica Communications Mar 2023Although various neurodegenerative disorders have been associated with coeliac disease (CD), the underlying neuropathological link between these brain and gut diseases...
Although various neurodegenerative disorders have been associated with coeliac disease (CD), the underlying neuropathological link between these brain and gut diseases remains unclear. We postulated that the neuronal damage sporadically observed in CD patients is immune-mediated. Our aim was to determine if the loss of neurons, especially Purkinje cells, coincides with microglia activation and T- and B-cell infiltration in the cerebellum of patients with CD and a concomitant idiopathic neurological disease affecting the cerebellum (NeuroCD). Post-mortem cerebellar tissue was collected of validated NeuroCD cases. Gender- and age-matched genetic spinocerebellar ataxia (SCA) controls and non-neurological controls (NNC) were selected based on clinical reports and pathological findings. Cerebellar tissue of seventeen patients was included (6 NeuroCD, 5 SCA, 6 NNC). In SCA cases we found that the Purkinje cell layer was 58.6% reduced in comparison with NNC. In NeuroCD cases this reduction was even more prominent with a median reduction of 81.3% compared to NNC. Marked increased numbers of both CD3+ and CD8+ cells were observed in the NeuroCD but not in SCA patients. This coincided with significantly more microglial reactivity in NeuroCD patients. These findings demonstrate that the massive loss of Purkinje cells in the cerebellum of neuro CD patients is accompanied by local innate and T-cell mediated immune responses.
Topics: Humans; Celiac Disease; Spinocerebellar Ataxias; Cerebellum; Purkinje Cells; Neurons; Nervous System Diseases
PubMed: 36966322
DOI: 10.1186/s40478-023-01538-5 -
Theranostics 2024The neurobiological basis of gaining consciousness from unconscious state induced by anesthetics remains unknown. This study was designed to investigate the involvement...
The neurobiological basis of gaining consciousness from unconscious state induced by anesthetics remains unknown. This study was designed to investigate the involvement of the cerebello-thalamus-motor cortical loop mediating consciousness transitions from the loss of consciousness (LOC) induced by an inhalational anesthetic sevoflurane in mice. The neural tracing and fMRI together with optochemogenetic manipulation were used to investigate the potential link among cerebello-thalamus-motor cortical brain regions. The fiber photometry of calcium and neurotransmitters, including glutamate (Glu), γ-aminobutyric acid (GABA) and norepinephrine (NE), were monitored from the motor cortex (M1) and the 5 lobule of the cerebellar vermis (5Cb) during unconsciousness induced by sevoflurane and gaining consciousness after sevoflurane exposure. Cerebellar Purkinje cells were optogenetically manipulated to investigate their influence on consciousness transitions during and after sevoflurane exposure. Activation of 5Cb Purkinje cells increased the Ca flux in the M1 CaMKIIα neurons, but this increment was significantly reduced by inactivation of posterior and parafascicular thalamic nucleus The 5Cb and M1 exhibited concerted calcium flux, and glutamate and GABA release during transitions from wakefulness, loss of consciousness, burst suppression to conscious recovery. Ca flux and Glu release in the M1, but not in the 5Cb, showed a strong synchronization with the EEG burst suppression, particularly, in the gamma-band range. In contrast, the Glu, GABA and NE release and Ca oscillations were coherent with the EEG gamma band activity only in the 5Cb during the pre-recovery of consciousness period. The optogenetic activation of Purkinje cells during burst suppression significantly facilitated emergence from anesthesia while the optogenetic inhibition prolonged the time to gaining consciousness. Our data indicate that cerebellar neuronal communication integrated with motor cortex through thalamus promotes consciousness recovery from anesthesia which may likely serve as arousal regulation.
Topics: Mice; Animals; Consciousness; Sevoflurane; Purkinje Cells; Calcium; Motor Cortex; Unconsciousness; Neurons; Anesthesia; Glutamates; gamma-Aminobutyric Acid
PubMed: 38169536
DOI: 10.7150/thno.89592 -
ELife Sep 2021Preterm infants that suffer cerebellar insults often develop motor disorders and cognitive difficulty. Excitatory granule cells, the most numerous neuron type in the...
Preterm infants that suffer cerebellar insults often develop motor disorders and cognitive difficulty. Excitatory granule cells, the most numerous neuron type in the brain, are especially vulnerable and likely instigate disease by impairing the function of their targets, the Purkinje cells. Here, we use regional genetic manipulations and in vivo electrophysiology to test whether excitatory neurons establish the firing properties of Purkinje cells during postnatal mouse development. We generated mutant mice that lack the majority of excitatory cerebellar neurons and tracked the structural and functional consequences on Purkinje cells. We reveal that Purkinje cells fail to acquire their typical morphology and connectivity, and that the concomitant transformation of Purkinje cell firing activity does not occur either. We also show that our mutant pups have impaired motor behaviors and vocal skills. These data argue that excitatory cerebellar neurons define the maturation time-window for postnatal Purkinje cell functions and refine cerebellar-dependent behaviors.
Topics: Action Potentials; Animals; Animals, Newborn; Basic Helix-Loop-Helix Transcription Factors; Cell Lineage; Excitatory Postsynaptic Potentials; Gene Deletion; Mice, Knockout; Motor Activity; Neurogenesis; Purkinje Cells; Synapses; Time Factors; Vesicular Glutamate Transport Protein 1; Vesicular Glutamate Transport Protein 2; Vocalization, Animal; Mice
PubMed: 34542409
DOI: 10.7554/eLife.68045 -
PLoS Genetics Apr 2022Polyglutamylation is a dynamic posttranslational modification where glutamate residues are added to substrate proteins by 8 tubulin tyrosine ligase-like (TTLL) family...
Polyglutamylation is a dynamic posttranslational modification where glutamate residues are added to substrate proteins by 8 tubulin tyrosine ligase-like (TTLL) family members (writers) and removed by the 6 member Nna1/CCP family of carboxypeptidases (erasers). Genetic disruption of polyglutamylation leading to hyperglutamylation causes neurodegenerative phenotypes in humans and animal models; the best characterized being the Purkinje cell degeneration (pcd) mouse, a mutant of the gene encoding Nna1/CCP1, the prototypic eraser. Emphasizing the functional importance of the balance between glutamate addition and elimination, loss of TTLL1 prevents Purkinje cell degeneration in pcd. However, whether Ttll1 loss protects other vulnerable neurons in pcd, or if elimination of other TTLLs provides protection is largely unknown. Here using a mouse genetic rescue strategy, we characterized the contribution of Ttll1, 4, 5, 7, or 11 to the degenerative phenotypes in cerebellum, olfactory bulb and retinae of pcd mutants. Ttll1 deficiency attenuates Purkinje cell loss and function and reduces olfactory bulb mitral cell death and retinal photoreceptor degeneration. Moreover, degeneration of photoreceptors in pcd is preceded by impaired rhodopsin trafficking to the rod outer segment and likely represents the causal defect leading to degeneration as this too is rescued by elimination of TTLL1. Although TTLLs have similar catalytic properties on model substrates and several are highly expressed in Purkinje cells (e.g. TTLL5 and 7), besides TTLL1 only TTLL4 deficiency attenuated degeneration of Purkinje and mitral cells in pcd. Additionally, TTLL4 loss partially rescued photoreceptor degeneration and impaired rhodopsin trafficking. Despite their common properties, the polyglutamylation profile changes promoted by TTLL1 and TTLL4 deficiencies in pcd mice are very different. We also report that loss of anabolic TTLL5 synergizes with loss of catabolic Nna1/CCP1 to promote photoreceptor degeneration. Finally, male infertility in pcd is not rescued by loss of any Ttll. These data provide insight into the complexity of polyglutamate homeostasis and function in vivo and potential routes to ameliorate disorders caused by disrupted polyglutamylation.
Topics: Animals; GTP-Binding Proteins; Glutamic Acid; Male; Phenotype; Purkinje Cells; Retinal Degeneration; Rhodopsin
PubMed: 35404950
DOI: 10.1371/journal.pgen.1010144 -
Journal of Anatomy Aug 2021Guinea pigs have proved useful as experimental animal models in studying cerebellar anatomical and structural alterations in human neurological disease; however, they...
Guinea pigs have proved useful as experimental animal models in studying cerebellar anatomical and structural alterations in human neurological disease; however, they are also currently acquiring increasing veterinary interest as companion animals. The morphometric features of the normal cerebellum in guinea pigs have not been previously investigated using stereology. The objective of the present work was to establish normal volumetric and quantitative stereological parameters for cerebellar tissues in guinea pigs, by means of unbiased design-based stereology. Cerebellar total volume, gray and white matter volume fractions, molecular and granular layers volume fractions, cerebellar surface area, Purkinje cellular and nuclear volumes, and the Purkinje cell total count were stereologically estimated. For this purpose, cerebellar hemispheres from six adult male guinea pigs were employed. Isotropic, uniform random sections were obtained by applying the orientator method, and subsequently processed for light microscopy. The cerebellar total volume, the white and grey matter volume fractions, and the molecular and granular layer volumes were estimated using the Cavalieri's principle and the point counting system. The cerebellar surface area was estimated through the use of test lines; Purkinje cellular and nuclear volumes were analysed using the nucleator technique, whereas the Purkinje cell total count was obtained by means of the optical disector technique. The mean ± standard deviation total volume of a guinea-pig cerebellar hemisphere was 0.11 ± 0.01 cm . The mean volumetric proportions occupied by the gray and white matters were, respectively, 78.0 ± 2.6% and 22.0 ± 2.6%, whereas their mean absolute volumes were found to be 0.21 ± 0.02 cm and 0.059 ± 0.006 cm . The volumes of the molecular and granular layers were estimated at 112.4 ± 20.6 mm and 104.4 ± 7.3 mm , whereas their mean thicknesses were calculated to be 0.184 ± 0.020 mm and 0.17 ± 0.02 mm. The molecular and granular layers accounted for 40.7 ± 3.9% and 37.4 ± 1.8% of total cerebellar volume respectively. The surface area of the cerebellum measured 611.4 ± 96.8 mm . Purkinje cells with a cellular volume of 3210.1 µm and with a nuclear volume of 470.9 µm had a higher incidence of occurrence. The mean total number of Purkinje cells for a cerebellar hemisphere was calculated to be 253,090 ± 34,754. The morphometric data emerging from the present study provide a set of reference data which might prove valuable as basic anatomical contribution for practical applications in veterinary neurology.
Topics: Animals; Cerebellum; Guinea Pigs; Male; Microscopy; Purkinje Cells
PubMed: 33763861
DOI: 10.1111/joa.13434 -
Neuroscience May 2021The cerebellum is a brain structure that is highly interconnected with other brain regions. There are many contributing factors to cerebellar-related brain disease, such... (Review)
Review
The cerebellum is a brain structure that is highly interconnected with other brain regions. There are many contributing factors to cerebellar-related brain disease, such as altered afferent input, local connectivity, and/or cerebellar output. Purkinje cells (PC) are the principle cells of the cerebellar cortex, and fire intrinsically; that is, they fire spontaneous action potentials at high frequencies. This review paper focuses on PC intrinsic firing activity, which is altered in multiple neurological diseases, including ataxia, Huntington Disease (HD) and autism spectrum disorder (ASD). Notably, there are several cases where interventions that restore or rescue PC intrinsic activity also improve impaired behavior in these mouse models of disease. These findings suggest that rescuing PC firing deficits themselves may be sufficient to improve impairment in cerebellar-related behavior in disease. We propose that restoring PC intrinsic firing represents a good target for drug development that might be of therapeutic use for several disorders.
Topics: Action Potentials; Animals; Ataxia; Autism Spectrum Disorder; Cerebellum; Mice; Purkinje Cells
PubMed: 32554108
DOI: 10.1016/j.neuroscience.2020.06.008 -
Proceedings of the National Academy of... Jun 2020Comparative transcriptomics between differentiating human pluripotent stem cells (hPSCs) and developing mouse neurons offers a powerful approach to compare genetic and... (Comparative Study)
Comparative Study
Comparative transcriptomics between differentiating human pluripotent stem cells (hPSCs) and developing mouse neurons offers a powerful approach to compare genetic and epigenetic pathways in human and mouse neurons. To analyze human Purkinje cell (PC) differentiation, we optimized a protocol to generate human pluripotent stem cell-derived Purkinje cells (hPSC-PCs) that formed synapses when cultured with mouse cerebellar glia and granule cells and fired large calcium currents, measured with the genetically encoded calcium indicator jRGECO1a. To directly compare global gene expression of hPSC-PCs with developing mouse PCs, we used translating ribosomal affinity purification (TRAP). As a first step, we used TRAP mice to profile actively transcribed genes in developing postnatal mouse PCs and used metagene projection to identify the most salient patterns of PC gene expression over time. We then created a transgenic - TRAP hPSC line to profile gene expression in differentiating hPSC-PCs, finding that the key gene expression pathways of differentiated hPSC-PCs most closely matched those of late juvenile mouse PCs (P21). Comparative bioinformatics identified classical PC gene signatures as well as novel mitochondrial and autophagy gene pathways during the differentiation of both mouse and human PCs. In addition, we identified genes expressed in hPSC-PCs but not mouse PCs and confirmed protein expression of a novel human PC gene, CD40LG, expressed in both hPSC-PCs and native human cerebellar tissue. This study therefore provides a direct comparison of hPSC-PC and mouse PC gene expression and a robust method for generating differentiated hPSC-PCs with human-specific gene expression for modeling developmental and degenerative cerebellar disorders.
Topics: Animals; Cell Differentiation; Humans; Mice; Pluripotent Stem Cells; Proteins; Purkinje Cells; Transcriptome
PubMed: 32546527
DOI: 10.1073/pnas.2000102117