cerebellar escape

BACKGROUND: It has been reported that the fastigial nucleus (FSN) plays an important role in the development of vascular dementia (VD). Both autophagy and inflammation are functionally involved in the pathogenesis of VD. In this study, we aimed to evaluate the therapeutic effect of electrical cerebellar fastigial nucleus stimulation (FNS) in VD treatment, as well as the effect of FNS on autophagy and inflammation. METHODS: A Morris water maze was used to evaluate the effect of FNS on the learning and memory ability of VD rats...

Transient expression of different NMDA receptors (NMDARs) plays a role in development of the cerebellum. Whether similar processes undergo during neuronal differentiation in culture is not clearly understood. We studied NMDARs in cerebellar neurons in cultures of 7 and 21 days in vitro (DIV) using immunocytochemical and electrophysiological approaches. Whereas at 7 DIV, the vast majority of neurons were immunopositive for GluN2 subunits, further synaptoginesis was accompanied by the time-dependent loss of NMDARs...

Both humans and laboratory animals suffering from cerebellar lesions exhibit cognitive as well as many emotional and behavioral abnormalities. These latter have been already observed in the cerebellar mutant mice currently used to highlight some aspect of autism spectrum disorders. The aim of this study was to investigate the influence of cerebellar-related stress response abnormalities on spatial learning and memory. Cerebellar-deficient Lurcher mutant mice were exposed to water environment without active escape possibility and then tested for spatial learning in the Morris water maze...

BACKGROUND: Artesunate (ART) is an antimalarial drug with potential anti-inflammatory effect. This study aimed to explore the potential protective role of ART in hepatic encephalopathy (HE), involving its function against ammonia toxicity. METHODS: HE rats were induced by the administration of thioacetamide (TAA, 300mg/kg/day). Spatial learning ability was tested in both Morris water and eight-arm radial maze. Rat cerebellar granule neurons (CGNs) were prepared for ammonia treatment in vitro, in line with SH-SY5Y and C6 cells...

Pur-alpha is a highly conserved sequence-specific DNA and RNA binding protein with established roles in DNA replication, RNA translation, cell cycle regulation, and maintenance of neuronal differentiation. Prior studies have shown that mice lacking Pur-alpha (-/-) display decreased neurogenesis and impaired neuronal differentiation. We sought to examine for the first time, the behavioral phenotype and brain histopathology of mice that are heterozygous (+/-) for Pur-alpha. Standardized behavioral phenotyping revealed a decreased escape response to touch, limb and abdominal hypotonia, and gait abnormalities in heterozygous Pur-alpha (+/-) mice, compared to wild-type (+/+) littermates...

The electrical stimulation of specific brain targets has been shown to induce striking antidepressant effects. Despite that recent data have indicated that cerebellum is involved in emotional regulation, the mechanisms by which stimulation improved mood-related behaviors in the cerebellum remained largely obscure. Here, we investigated the stimulation effects of the ventromedial prefrontal cortex (vmPFC), nucleus accumbens (NAc), and lateral habenular nucleus on the c-Fos neuronal activity in various deep cerebellar and vestibular nuclei using the unpredictable chronic mild stress (CMS) animal model of depression...

Friedreich's ataxia (FRDA) is an inherited neurodegenerative disease. The mutation consists of a GAA repeat expansion within the FXN gene, which downregulates frataxin, leading to abnormal mitochondrial iron accumulation, which may in turn cause changes in mitochondrial function. Although, many studies of FRDA patients and mouse models have been conducted in the past two decades, the role of frataxin in mitochondrial pathophysiology remains elusive. Are the mitochondrial abnormalities only a side effect of the increased accumulation of reactive iron, generating oxidative stress? Or does the progressive lack of iron-sulphur clusters (ISCs), induced by reduced frataxin, cause an inhibition of the electron transport chain complexes (CI, II and III) leading to reactive oxygen species escaping from oxidative phosphorylation reactions? To answer these crucial questions, we have characterised the mitochondrial pathophysiology of a group of disease-relevant and readily accessible neurons, cerebellar granule cells, from a validated FRDA mouse model...

Experimental evidence suggests that the cerebellum plays a more complex role in learning than simply regulating the motor response. Rather, it is thought to play a significant role in the consolidation of emotional memory in mice. Due to the difficulty of interpreting fear and anxiety behaviors-the standard methodology for the study of the histaminergic system and emotional memory-in mice, we propose a behavioral assessment of mice subjected to the Elevated T-maze after histamine microinjection of the cerebellar vermis...

The paradigm of a single gene associated with one specific phenotype and mode of inheritance has been repeatedly challenged. Genotype-phenotype correlations can often be traced to different mutation types, localization of the variants in distinct protein domains, or the trigger of or escape from nonsense-mediated decay. Using whole-exome sequencing, we identified homozygous variants in EMC1 that segregated with a phenotype of developmental delay, hypotonia, scoliosis, and cerebellar atrophy in three families...

Pavlovian conditioning underlies many aspects of pain behavior, including fear and threat detection [1], escape and avoidance learning [2], and endogenous analgesia [3]. Although a central role for the amygdala is well established [4], both human and animal studies implicate other brain regions in learning, notably ventral striatum and cerebellum [5]. It remains unclear whether these regions make different contributions to a single aversive learning process or represent independent learning mechanisms that interact to generate the expression of pain-related behavior...

Holmes proposed not only the term ataxia, but also opposite clinical signs related to muscle recruitment, which have escaped clinical attention; (1) asthenia, representing delay in initiating muscle contraction and slowness in attaining exertion of full power, and (2) adventitiousness, representing adventitious movements. Recent physiological studies have shown that cerebellar outputs are modified by release or facilitation of Purkinje cell-mediated inhibition on dentate neurons. We believe that asthenia and adventitiousness, which correlate with deficits in the control of disinhibition and inhibition, respectively, deserve more attention in clinical examination...

UNLABELLED: The periaqueductal gray (PAG) coordinates behaviors essential to survival, including striking changes in movement and posture (e.g., escape behaviors in response to noxious stimuli vs freezing in response to fear-evoking stimuli). However, the neural circuits underlying the expression of these behaviors remain poorly understood. We demonstrate in vivo in rats that activation of the ventrolateral PAG (vlPAG) affects motor systems at multiple levels of the neuraxis through the following: (1) differential control of spinal neurons that forward sensory information to the cerebellum via spino-olivo-cerebellar pathways (nociceptive signals are reduced while proprioceptive signals are enhanced); (2) alterations in cerebellar nuclear output as revealed by changes in expression of Fos-like immunoreactivity; and (3) regulation of spinal reflex circuits, as shown by an increase in α-motoneuron excitability...

Human ZIC1 (zinc finger protein of cerebellum 1), one of five homologs of the Drosophila pair-rule gene odd-paired, encodes a transcription factor previously implicated in vertebrate brain development. Heterozygous deletions of ZIC1 and its nearby paralog ZIC4 on chromosome 3q25.1 are associated with Dandy-Walker malformation of the cerebellum, and loss of the orthologous Zic1 gene in the mouse causes cerebellar hypoplasia and vertebral defects. We describe individuals from five families with heterozygous mutations located in the final (third) exon of ZIC1 (encoding four nonsense and one missense change) who have a distinct phenotype in which severe craniosynostosis, specifically involving the coronal sutures, and variable learning disability are the most characteristic features...

BACKGROUND: Medulloblastomas are malignant childhood brain tumors that arise due to the aberrant activity of developmental pathways during postnatal cerebellar development and in adult humans. Transcriptome analysis has identified four major medulloblastoma subgroups. One of them, the Sonic hedgehog (SHH) subgroup, is caused by aberrant Hedgehog signal transduction due to mutations in the Patched1 (PTCH1) receptor or downstream effectors. Mice carrying a Patched-1 null allele (Ptch1∆/+) are a good model to study the alterations underlying medulloblastoma development as a consequence of aberrant Hedgehog pathway activity...

Atrophy of large neurons in the dentate nucleus (DN) is an important pathologic correlate of neurologic disability in patients with Friedreich ataxia (FA). Thinning of the DN was quantified in 29 autopsy cases of FA and 2 carriers by measuring the thickness of the gray matter ribbon on stains with anti-glutamic acid decarboxylase, the rate-limiting enzyme in the biosynthesis of γ-amino-butyric acid (GABA). The DN was thinner than normal in all cases of FA, and atrophy correlated inversely with disease duration but not with age at onset or length of the homozygous guanine-adenine-adenine trinucleotide expansions...

OBJECTIVE: To identify the genetic cause of autosomal dominant spinocerebellar ataxia type 28 (SCA28) with ptosis in 2 Belgian families without AFG3L2 point mutations and further extend the clinical spectrum of SCA28 through the study of a brain autopsy, advanced MRI, and cell-based functional assays exploring the underlying disease mechanism. METHODS: Two large families were clinically examined in detail. Linkage analysis and multiplex amplicon quantification were performed...

Loss-of-function mutations in PAK3 contribute to non-syndromic X-linked intellectual disability (NS-XLID) by affecting dendritic spine density and morphology. Linkage analysis in a three-generation family with affected males showing ID, agenesis of corpus callosum, cerebellar hypoplasia, microcephaly and ichthyosis, revealed a candidate disease locus in Xq21.33q24 encompassing over 280 genes. Subsequent to sequencing all coding exons of the X chromosome, we identified a single novel variant within the linkage region, affecting a conserved codon of PAK3...

Electric fields of synaptic currents can influence diffusion of charged neurotransmitters, such as glutamate, in the synaptic cleft. However, this phenomenon has hitherto been detected only through sustained depolarization of large principal neurons, and its adaptive significance remains unknown. Here, we find that in cerebellar synapses formed on electrically compact granule cells, a single postsynaptic action potential can retard escape of glutamate released into the cleft. This retardation boosts activation of perisynaptic group I metabotropic glutamate receptors (mGluRs), which in turn rapidly facilitates local NMDA receptor currents...

OFD1, now recognized as a ciliopathy, is characterized by malformations of the face, oral cavity and digits, and is transmitted as an X-linked condition with lethality in males. Mutations in OFD1 also cause X-linked Joubert syndrome (JBTS10) and Simpson-Golabi-Behmel syndrome type 2 (SGBS2). We have studied 55 sporadic and six familial cases of suspected OFD1. Comprehensive mutation analysis in OFD1 revealed mutations in 37 female patients from 30 families; 22 mutations have not been previously described including two heterozygous deletions spanning OFD1 and neighbouring genes...

Homozygous Dab1(scm) mouse mutants with cell ectopias in cerebellar cortex, hippocampus, and neocortex were compared to non-ataxic controls on the SHIRPA primary screening battery on postnatal days 8, 15, and 22, as well as in the adult period. Dab1(scm) mutants were distinguished from non-ataxic controls as early as postnatal day 8 based on body tremor, gait anomalies, and body weight. On postnatal day 15, motor coordination deficits were evident on horizontal bar and inclined or vertical grid tests in association with a weaker grip strength...