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1.
Neurobiol Dis ; 199: 106600, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38996985

RESUMO

Familial Dysautonomia (FD) is an autosomal recessive disorder caused by a splice site mutation in the gene ELP1, which disproportionally affects neurons. While classically characterized by deficits in sensory and autonomic neurons, neuronal defects in the central nervous system have also been described. Although ELP1 expression remains high in the normal developing and adult cerebellum, its role in cerebellar development is unknown. To explore the role of Elp1 in the cerebellum, we knocked out Elp1 in cerebellar granule cell progenitors (GCPs) and examined the outcome on animal behavior and cellular composition. We found that GCP-specific conditional knockout of Elp1 (Elp1cKO) resulted in ataxia by 8 weeks of age. Cellular characterization showed that the animals had smaller cerebella with fewer granule cells. This defect was already apparent as early as 7 days after birth, when Elp1cKO animals also had fewer mitotic GCPs and shorter Purkinje dendrites. Through molecular characterization, we found that loss of Elp1 was associated with an increase in apoptotic cell death and cell stress pathways in GCPs. Our study demonstrates the importance of ELP1 in the developing cerebellum, and suggests that loss of Elp1 in the GC lineage may also play a role in the progressive ataxia phenotypes of FD patients.

2.
Neurosci Biobehav Rev ; 164: 105791, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38960075

RESUMO

Despite over two decades of neuroimaging research, a unanimous definition of the pattern of structural variation associated with autism spectrum disorder (ASD) has yet to be found. One potential impeding issue could be the sometimes ambiguous use of measurements of variations in gray matter volume (GMV) or gray matter concentration (GMC). In fact, while both can be calculated using voxel-based morphometry analysis, these may reflect different underlying pathological mechanisms. We conducted a coordinate-based meta-analysis, keeping apart GMV and GMC studies of subjects with ASD. Results showed distinct and non-overlapping patterns for the two measures. GMV decreases were evident in the cerebellum, while GMC decreases were mainly found in the temporal and frontal regions. GMV increases were found in the parietal, temporal, and frontal brain regions, while GMC increases were observed in the anterior cingulate cortex and middle frontal gyrus. Age-stratified analyses suggested that such variations are dynamic across the ASD lifespan. The present findings emphasize the importance of considering GMV and GMC as distinct yet synergistic indices in autism research.

3.
MedComm (2020) ; 5(7): e638, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39006764

RESUMO

The cerebellum is crucial for both motor and nonmotor functions. Alzheimer's disease (AD), alongside other dementias such as vascular dementia (VaD), Lewy body dementia (DLB), and frontotemporal dementia (FTD), as well as other neurodegenerative diseases (NDs) like Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and spinocerebellar ataxias (SCA), are characterized by specific and non-specific neurodegenerations in central nervous system. Previously, the cerebellum's significance in these conditions was underestimated. However, advancing research has elevated its profile as a critical node in disease pathology. We comprehensively review the existing evidence to elucidate the relationship between cerebellum and the aforementioned diseases. Our findings reveal a growing body of research unequivocally establishing a link between the cerebellum and AD, other forms of dementia, and other NDs, supported by clinical evidence, pathological and biochemical profiles, structural and functional neuroimaging data, and electrophysiological findings. By contrasting cerebellar observations with those from the cerebral cortex and hippocampus, we highlight the cerebellum's distinct role in the disease processes. Furthermore, we also explore the emerging therapeutic potential of targeting cerebellum for the treatment of these diseases. This review underscores the importance of the cerebellum in these diseases, offering new insights into the disease mechanisms and novel therapeutic strategies.

4.
Neurourol Urodyn ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38962955

RESUMO

OBJECTIVES: The objective of this study is to explore the functional connectivity (FC) of the cerebellum during the storage phase of micturition, through detecting spontaneous blood-oxygen-level dependent signal between the cerebellum and different brain regions using a high-resolution 7 Tesla magnetic resonance imaging (MRI) scanner. MATERIALS AND METHODS: We recruited healthy individuals with no reported history of neurological disease or lower urinary tract (LUT) symptoms. Participants were asked to drink 500 mL of water and then empty their bladders before entering the MRI scanner. They underwent a T1-weighted anatomical scan, followed by an initial (8 min) empty bladder resting state functional MRI (rs-fMRI) acquisition. Once subjects felt the desire to void, a second rs-fMRI scan was obtained, this time with a full bladder state. We established a priori cerebellar regions of interest from the literature to perform seed-to-voxel analysis using nonparametric statistics based on the Threshold Free Cluster Enhancement method and utilized a voxel threshold of p < 0.05. RESULTS: Twenty individuals (10 male and 10 female) with a median age of 25 years (IQR [3.5]) participated in the study. We placed 31 different 4-mm spherical seeds throughout the cerebellum and assessed their FC with the remainder of the brain. Three of these (left cerebellar tonsil, right posterolateral lobe, right posterior lobe) showed significant differences in connectivity when comparing scans conducted with a full bladder to those with an empty bladder. Additionally, we observed sex differences in FC, with connectivity being higher in women during the empty bladder condition. CONCLUSION: Our initial findings reveal, for the first time, that the connectivity of the cerebellar network is modulated by bladder filling and is associated with LUT function. Unraveling the cerebellum's role in bladder function lays the foundation for a more comprehensive understanding of urinary pathologies affecting this area.

5.
Artigo em Inglês | MEDLINE | ID: mdl-38963083

RESUMO

Reports from recent years provide compelling evidence about the structure and the existence of functional topography in the cerebellum. However, most of them focused on the motor functions of the cerebellum. Recent studies suggest the involvement of the posterior lobe of the cerebellum in the context of neurodegenerative and cognitive disorders. The pathophysiology of these diseases is not sufficiently understood, and recent studies indicate that it could also affect additional subregions of the cerebellum. Anatomical and clinical studies, combined with neuroimaging, provide new ways of thinking about the organization and functioning of the cerebellum. This review summarizes knowledge about the topography and functions of the cerebellum, and focuses on its anatomical and functional contributions to the development of neurological diseases.

6.
J Clin Neurol ; 20(4): 378-384, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38951972

RESUMO

BACKGROUND AND PURPOSE: Repetitive transcranial magnetic stimulation (rTMS) of the cerebellar hemisphere represents a new option in treating essential tremor (ET) patients. We aimed to determine the efficacy of cerebellar rTMS in treating ET using different protocols regarding the number of sessions, exposure duration, and follow-up duration. METHODS: A randomized sham-controlled trial was conducted, in which 45 recruit patients were randomly allocated to 2 groups. The first (active group) comprised 23 patients who were exposed to 12 sessions of active rTMS with 900 pulses of 1-Hz rTMS at 90% of the resting motor threshold daily on each side of the cerebellar hemispheres over 4 weeks. The second group (sham group) comprised 22 patients who were exposed to 12 sessions of sham rTMS. Both groups were reassessed at baseline and after 1 day, 1 month, 2 months, and 3 months using the Fahn-Tolosa-Marin tremor-rating scale (FTM). RESULTS: Demographic characteristics did no differ between the two groups. There were significant reductions both in FTM subscores A and B and in the FTM total score in the active-rTMS group during the period of assessment and after 3 months (p=0.031 and 0.011, respectively). However, subscore C did not change significantly from baseline when assessed at 2 and 3 months (p=0.073 and 0.236, respectively). Furthermore, the global assessment score was significantly higher in the active-rTMS group (p>0.001). CONCLUSIONS: Low-frequency rTMS over the cerebellar cortex for 1 month showed relative safety and long-lasting efficacy in patients with ET. Further large-sample clinical trials are needed that include different sites of stimulation and longer follow-ups.

7.
AIMS Neurosci ; 11(2): 118-143, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38988888

RESUMO

The beneficial effects of Prosopis africana (PA) on human health have been demonstrated; however, its protective effects against heavy metals (HM) are not yet understood. This study evaluated the potential neuroprotective effects of PA in the cerebral cortex and cerebellum. To accomplish this, we divided 35 albino Sprague Dawley rats into five groups. Group I did not receive either heavy metal mixture (HMM) or PA. Group II received a HMM of PbCl2 (20 mg/kg), CdCl2 (1.61 mg/kg), HgCl2 (0.40 mg/kg), and NaAsO3 (10 mg/kg) orally for a period of two months. Groups III, IV, and V received HMM along with PA at doses of 500, 1000, and 1500 mg/kg, respectively. PA caused decreased levels of HM accumulation in the cerebral cortex and cerebellum and improved performance in the Barnes maze and rotarod tests. PA significantly reduced levels of IL-6 and TNF-α. PA increased concentrations of SOD, CAT, GSH, and Hmox-1 and decreased the activities of AChE and Nrf2. In addition, levels of MDA and NO decreased in groups III, IV, and V, along with an increase in the number of live neurons. In conclusion, PA demonstrates a complex neuroprotective effect with the potential to alleviate various aspects of HM-induced neurotoxicity.

8.
Hum Brain Mapp ; 45(10): e26749, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38989605

RESUMO

The cerebellum has been involved in social abilities and autism. Given that the cerebellum is connected to the cortex via the cerebello-thalamo-cortical loop, the connectivity between the cerebellum and cortical regions involved in social interactions, that is, the right temporo-parietal junction (rTPJ) has been studied in individuals with autism, who suffer from prototypical deficits in social abilities. However, existing studies with small samples of categorical, case-control comparisons have yielded inconsistent results due to the inherent heterogeneity of autism, suggesting that investigating how clinical dimensions are related to cerebellar-rTPJ functional connectivity might be more relevant. Therefore, our objective was to study the functional connectivity between the cerebellum and rTPJ, focusing on its association with social abilities from a dimensional perspective in a transdiagnostic sample. We analyzed structural magnetic resonance imaging (MRI) and functional MRI (fMRI) scans obtained during naturalistic films watching from a large transdiagnostic dataset, the Healthy Brain Network (HBN), and examined the association between cerebellum-rTPJ functional connectivity and social abilities measured with the social responsiveness scale (SRS). We conducted univariate seed-to-voxel analysis, multivariate canonical correlation analysis (CCA), and predictive support vector regression (SVR). We included 1404 subjects in the structural analysis (age: 10.516 ± 3.034, range: 5.822-21.820, 506 females) and 414 subjects in the functional analysis (age: 11.260 ± 3.318 years, range: 6.020-21.820, 161 females). Our CCA model revealed a significant association between cerebellum-rTPJ functional connectivity, full-scale IQ (FSIQ) and SRS scores. However, this effect was primarily driven by FSIQ as suggested by SVR and univariate seed-to-voxel analysis. We also demonstrated the specificity of the rTPJ and the influence of structural anatomy in this association. Our results suggest that there is a complex relationship between cerebellum-rTPJ connectivity, social performance and IQ. This relationship is specific to the cerebellum-rTPJ connectivity, and is largely related to structural anatomy in these two regions. PRACTITIONER POINTS: We analyzed cerebellum-right temporoparietal junction (rTPJ) connectivity in a pediatric transdiagnostic sample. We found a complex relationship between cerebellum and rTPJ connectivity, social performance and IQ. Cerebellum and rTPJ functional connectivity is related to structural anatomy in these two regions.


Assuntos
Cerebelo , Imageamento por Ressonância Magnética , Humanos , Cerebelo/diagnóstico por imagem , Cerebelo/fisiopatologia , Cerebelo/patologia , Masculino , Feminino , Adulto Jovem , Adulto , Conectoma/métodos , Habilidades Sociais , Adolescente , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiopatologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Vias Neurais/fisiopatologia , Vias Neurais/diagnóstico por imagem
9.
Diagnostics (Basel) ; 14(13)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39001305

RESUMO

The impact of ethanol on the fetus is a significant concern as an estimated 2-5% of live births may be affected by prenatal alcohol exposure. This exposure can lead to various functional and structural abnormalities in the cerebral cortex, basal ganglia, diencephalon, and cerebellum, resulting in region-specific symptoms. The deficits relate to the motor and cognitive domains, affecting, in particular, general intelligence, attention, executive functions, language, memory, visual perception, and social skills-collectively called the fetal alcohol spectrum disorder (FASD). Recent studies suggest that damage to the developing cerebellum (in form of alcohol exposure) can impair the cortical targets of the cerebello-thalamo-cortical tract. This malfunction in the cerebello-cerebral loop optimization may be due to disruptions in the formation of the foundational elements of the internal model within the developing cerebellum. Alcohol exposure targets multiple nodes in the reciprocal loops between the cerebellum and cerebral cortex. Here, we examine the possibility that prenatal alcohol exposure damages the developing cerebellum and disrupts the connectivity within the cerebello-cerebral neuronal circuits, exacerbating FASD-related cortical dysfunctions. We propose that malfunctions between cerebellar internal model (critically involved in predictions) and cerebral regions contribute to the deficits observed in FASD. Given the major role of the cerebellum in motor, cognitive, and affective functions, we suggest that therapies should target these malfunctions to mitigate the burden of FASD. We discuss the concept of therapies oriented towards malfunctioning cerebello-cerebral loops (TOMCCLs), emphasizing anti-inflammatory strategies and treatments aimed at modulating cerebellar myelination to restore optimal and predictive cerebello-cerebral functions.

10.
Cells ; 13(13)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38994990

RESUMO

In zebrafish, like in mammals, radial glial cells (RGCs) can act as neural progenitors during development and regeneration in adults. However, the heterogeneity of glia subpopulations entails the need for different specific markers of zebrafish glia. Currently, fluorescent protein expression mediated by a regulatory element from the glial fibrillary acidic protein (gfap) gene is used as a prominent glia reporter. We now expand this tool by demonstrating that a regulatory element from the mouse Fatty acid binding protein 7 (Fabp7) gene drives reliable expression in fabp7-expressing zebrafish glial cells. By using three different Fabp7 regulatory element-mediated fluorescent protein reporter strains, we reveal in double transgenic zebrafish that progenitor cells expressing fluorescent proteins driven by the Fabp7 regulatory element give rise to radial glia, oligodendrocyte progenitors, and some neuronal precursors. Furthermore, Bergmann glia represent the almost only glial population of the zebrafish cerebellum (besides a few oligodendrocytes), and the radial glia also remain in the mature cerebellum. Fabp7 regulatory element-mediated reporter protein expression in Bergmann glia progenitors suggests their origin from the ventral cerebellar proliferation zone, the ventricular zone, but not from the dorsally positioned upper rhombic lip. These new Fabp7 reporters will be valuable for functional studies during development and regeneration.


Assuntos
Animais Geneticamente Modificados , Proteína 7 de Ligação a Ácidos Graxos , Peixe-Zebra , Animais , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteína 7 de Ligação a Ácidos Graxos/metabolismo , Proteína 7 de Ligação a Ácidos Graxos/genética , Neuroglia/metabolismo , Cerebelo/metabolismo , Cerebelo/citologia , Oligodendroglia/metabolismo , Oligodendroglia/citologia , Camundongos , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética
11.
Artigo em Inglês | MEDLINE | ID: mdl-38995373

RESUMO

Mercury chloride (ME) is a chemical pollutant commonly found in the environment, which can contribute to undesirable health consequence worldwide. The current study investigated the detrimental impact of ME on the cerebellum and spinal cord tissues in 6-8-week-old female rats. We also evaluated the neuroprotective efficacy of ß-caryophyllene (BC) against spinal and cerebellar changes caused by ME. Thirty-five young Wistar albino rats were randomly chosen and assigned into five groups: control (CO), olive oil (OI), ME, BC, ME + BC. All samples were analysed by means of unbiased stereological, biochemical, immunohistochemical, and histopathological methods. Our biochemical findings showed that SOD level was significantly increased in the ME group compared to the CO group (p < 0.05). We additionally detected a statistically significant decrease in the number of cerebellar Purkinje cells and granular cells, as well as spinal motor neuron in the ME group compared to the CO group (p < 0.05). In the ME + BC group, the number of Purkinje cells, granular cells, and spinal motor neurons was significantly higher compared to the ME group (p < 0.05). Decreased SOD activity in the ME + BC group was also detected than the ME group (p < 0.05). Immunohistochemical (the tumour necrosis factor-alpha (TNF-α)) and histopathological examinations also exhibited crucial information in each of the group. Taken together, ME exposure was associated with neurotoxicity in the cerebellum and spinal cord tissues. BC treatment also mitigated ME-induced neurological alteration, which may imply its potential therapeutic benefits.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38953397

RESUMO

AIMS: The cerebellum is involved in higher-order mental processing as well as sensorimotor functions. Although structural abnormalities in the cerebellum have been demonstrated in schizophrenia, neuroimaging techniques are not yet applicable to identify them given the lack of biomarkers. We aimed to develop a robust diagnostic model for schizophrenia using radiomic features from T1-weighted magnetic resonance imaging (T1-MRI) of the cerebellum. METHODS: A total of 336 participants (174 schizophrenia; 162 healthy controls [HCs]) were allocated to training (122 schizophrenia; 115 HCs) and test (52 schizophrenia; 47 HCs) cohorts. We obtained 2568 radiomic features from T1-MRI of the cerebellar subregions. After feature selection, a light gradient boosting machine classifier was trained. The discrimination and calibration of the model were evaluated. SHapley Additive exPlanations (SHAP) was applied to determine model interpretability. RESULTS: We identified 17 radiomic features to differentiate participants with schizophrenia from HCs. In the test cohort, the radiomics model had an area under the curve, accuracy, sensitivity, and specificity of 0.89 (95% confidence interval: 0.82-0.95), 78.8%, 88.5%, and 75.4%, respectively. The model explanation by SHAP suggested that the second-order size zone non-uniformity feature from the right lobule IX and first-order energy feature from the right lobules V and VI were highly associated with the risk of schizophrenia. CONCLUSION: The radiomics model focused on the cerebellum demonstrates robustness in diagnosing schizophrenia. Our results suggest that microcircuit disruption in the posterior cerebellum is a disease-defining feature of schizophrenia, and radiomics modeling has potential for supporting biomarker-based decision-making in clinical practice.

13.
Psychon Bull Rev ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38954157

RESUMO

Sensory attenuation refers to the reduction in sensory intensity resulting from self-initiated actions compared to stimuli initiated externally. A classic example is scratching oneself without feeling itchy. This phenomenon extends across various sensory modalities, including visual, auditory, somatosensory, and nociceptive stimuli. The internal forward model proposes that during voluntary actions, an efferent copy of the action command is sent out to predict sensory feedback. This predicted sensory feedback is then compared with the actual sensory feedback, leading to the suppression or reduction of sensory stimuli originating from self-initiated actions. To further elucidate the neural mechanisms underlying sensory attenuation effect, we conducted an extensive meta-analysis of functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) studies. Utilizing activation likelihood estimation (ALE) analysis, our results revealed significant activations in a prominent cluster encompassing the right superior temporal gyrus (rSTG), right middle temporal gyrus (rMTG), and right insula when comparing external-generated with self-generated conditions. Additionally, significant activation was observed in the right anterior cerebellum when comparing self-generated to external-generated conditions. Further analysis using meta-analytic connectivity modeling (MACM) unveiled distinct brain networks co-activated with the rMTG and right cerebellum, respectively. Based on these findings, we propose that sensory attenuation arises from the suppression of reflexive inputs elicited by self-initiated actions through the internal forward modeling of a cerebellum-centered action prediction network, enabling the "sensory conflict detection" regions to effectively discriminate between inputs resulting from self-induced actions and those originating externally.

14.
Acta Neurol Belg ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954167

RESUMO

PURPOSE: To preliminarily investigate the reliability and validity of the Chinese version of the Cerebellar Cognitive Affective Syndrome Scale (CCAS scale) in the cerebellar injury population. METHODS: In this study, 40 patients with cerebellar injury and 39 normal individuals hospitalized in a stroke center were assessed using the Chinese version of the CCAS scale A, MMSE, and PHQ2, and the results were analyzed using content validity, structural validity, internal consistency, inter- rater agreement, and test-retest reliability. RESULTS: The correlation coefficients of semantic fluency, phonemic fluency, category switching, digit span forward, digit span backward, cube, verbal recall, similarities and Go No-Go subscores in the Chinese version of the CCAS scale A were 0.586-0.831 (P ≤ 0.05) with the total score, but there was no significant correlation between the affect and the total score (P = 0.110). The total cognitive score of the Chinese version of the CCAS scale A was correlated with the (r = 0.807, P ≤ 0.01), and the total score of the Chinese version of the CCAS scale A affect was correlated with the total score of PHQ2 (r = 0.884, P ≤ 0.01). The 2 factors were extracted using principal component analysis, and the cumulative variance contribution rate was 59.633%. The factor loadings of each of the corresponding factors were > 0.5, indicating good structural validity of the Chinese version of the CCAS scale A. Cronbach α = 0.827 indicated good internal consistency, and inter-rater reliability (ICC > 0.95) and test-retest reliability (ICC = 0.717-0.895)indicated that the Chinese version of the CCAS scale A had good inter-rater reliability and test-retest reliability. CONCLUSION: The Chinese version of the CCAS scale A has good reliability and validity in the cerebellar injury population and is useful for screening cerebellar cognitive-emotional syndrome.

15.
Cell Rep Methods ; : 100816, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38981474

RESUMO

We developed a method that utilizes fluorescent labeling of nuclear envelopes alongside cytometry sorting for the selective isolation of Purkinje cell (PC) nuclei. Beginning with SUN1 reporter mice, we GFP-tagged envelopes to confirm that PC nuclei could be accurately separated from other cell types. We then developed an antibody-based protocol to make PC nuclear isolation more robust and adaptable to cerebellar tissues of any genotypic background. Immunofluorescent labeling of the nuclear membrane protein RanBP2 enabled the isolation of PC nuclei from C57BL/6 cerebellum. By analyzing the expression of PC markers, nuclear size, and nucleoli number, we confirmed that our method delivers a pure fraction of PC nuclei. To demonstrate its applicability, we isolated PC nuclei from spinocerebellar ataxia type 7 (SCA7) mice and identified transcriptional changes in known and new disease-associated genes. Access to pure PC nuclei offers insights into PC biology and pathology, including the nature of selective neuronal vulnerability.

16.
Elife ; 122024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38953282

RESUMO

The enhancement of associative synaptic plasticity often results in impaired rather than enhanced learning. Previously, we proposed that such learning impairments can result from saturation of the plasticity mechanism (Nguyen-Vu et al., 2017), or, more generally, from a history-dependent change in the threshold for plasticity. This hypothesis was based on experimental results from mice lacking two class I major histocompatibility molecules, MHCI H2-Kb and H2-Db (MHCI KbDb-/-), which have enhanced associative long-term depression at the parallel fiber-Purkinje cell synapses in the cerebellum (PF-Purkinje cell LTD). Here, we extend this work by testing predictions of the threshold metaplasticity hypothesis in a second mouse line with enhanced PF-Purkinje cell LTD, the Fmr1 knockout mouse model of Fragile X syndrome (FXS). Mice lacking Fmr1 gene expression in cerebellar Purkinje cells (L7-Fmr1 KO) were selectively impaired on two oculomotor learning tasks in which PF-Purkinje cell LTD has been implicated, with no impairment on LTD-independent oculomotor learning tasks. Consistent with the threshold metaplasticity hypothesis, behavioral pre-training designed to reverse LTD at the PF-Purkinje cell synapses eliminated the oculomotor learning deficit in the L7-Fmr1 KO mice, as previously reported in MHCI KbDb-/-mice. In addition, diazepam treatment to suppress neural activity and thereby limit the induction of associative LTD during the pre-training period also eliminated the learning deficits in L7-Fmr1 KO mice. These results support the hypothesis that cerebellar LTD-dependent learning is governed by an experience-dependent sliding threshold for plasticity. An increased threshold for LTD in response to elevated neural activity would tend to oppose firing rate stability, but could serve to stabilize synaptic weights and recently acquired memories. The metaplasticity perspective could inform the development of new clinical approaches for addressing learning impairments in autism and other disorders of the nervous system.


Assuntos
Modelos Animais de Doenças , Proteína do X Frágil da Deficiência Intelectual , Síndrome do Cromossomo X Frágil , Camundongos Knockout , Células de Purkinje , Animais , Síndrome do Cromossomo X Frágil/fisiopatologia , Síndrome do Cromossomo X Frágil/genética , Camundongos , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Células de Purkinje/metabolismo , Plasticidade Neuronal , Masculino , Aprendizagem
17.
Front Neuroanat ; 18: 1396829, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962392

RESUMO

Introduction: Recurrent isolated sleep paralysis (RISP) is a rapid eye movement sleep (REM) parasomnia, characterized by the loss of voluntary movements upon sleep onset and/or awakening with preserved consciousness. Evidence suggests microstructural changes of sleep in RISP, although the mechanism of this difference has not been clarified yet. Our research aims to identify potential morphological changes in the brain that can reflect these regulations. Materials and methods: We recruited 10 participants with RISP (8 women; mean age 24.7 years; SD 2.4) and 10 healthy control subjects (w/o RISP; 3 women; mean age 26.3 years; SD 3.7). They underwent video-polysomnography (vPSG) and sleep macrostructure was analyzed. After that participants underwent magnetic resonance imaging (MRI) of the brain. We focused on 2-dimensional measurements of cerebellum, pons and thalamus. Statistical analysis was done in SPSS program. After analysis for normality we performed Mann-Whitney U test to compare our data. Results: We did not find any statistically significant difference in sleep macrostructure between patients with and w/o RISP. No evidence of other sleep disturbances was found. 2-dimensional MRI measurements revealed statistically significant increase in cerebellar vermis height (p = 0.044) and antero-posterior diameter of midbrain-pons junction (p = 0.018) in RISP compared to w/o RISP. Discussion: Our results suggest increase in size of cerebellum and midbrain-pons junction in RISP. This enlargement could be a sign of an over-compensatory mechanism to otherwise dysfunctional regulatory pathways. Further research should be done to measure these differences in time and with closer respect to the frequency of RISP episodes.

18.
J Anat ; 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38970393

RESUMO

The nuclei are the main output structures of the cerebellum. Each and every cerebellar cortical computation reaches several areas of the brain by means of cerebellar nuclei processing and integration. Nevertheless, our knowledge of these structures is still limited compared to the cerebellar cortex. Here, we present a mouse genetic inducible fate-mapping study characterizing rhombic lip-derived glutamatergic neurons of the nuclei, the most conspicuous family of long-range cerebellar efferent neurons. Glutamatergic neurons mainly occupy dorsal and lateral territories of the lateral and interposed nuclei, as well as the entire medial nucleus. In mice, they are born starting from about embryonic day 9.5, with a peak between 10.5 and 12.5, and invade the nuclei with a lateral-to-medial progression. While some markers label a heterogeneous population of neurons sharing a common location (BRN2), others appear to be lineage specific (TBR1, LMX1a, and MEIS2). A comparative analysis of TBR1 and LMX1a distributions reveals an incomplete overlap in their expression domains, in keeping with the existence of separate efferent subpopulations. Finally, some tagged glutamatergic progenitors are not labeled by any of the markers used in this study, disclosing further complexity. Taken together, our results obtained in late embryonic nuclei shed light on the heterogeneity of the excitatory neuron pool, underlying the diversity in connectivity and functions of this largely unexplored cerebellar territory. Our findings contribute to laying the groundwork for a comprehensive functional analysis of nuclear neuron subpopulations.

19.
Behav Brain Res ; : 115136, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38971431

RESUMO

Gestational exposure to valproic acid (VPA) is a risk factor for autism spectrum disorder (ASD). Rodents exposed to VPA in utero display common features of ASD, including volumetric dysregulation in higher-order cognitive regions like the medial prefrontal cortex (mPFC), the anterior cingulate cortex (ACC), and the hippocampus. Exercise has been shown in elderly populations to boost cognition and to buffer against brain volume losses with age. This study employed an adolescent treadmill exercise intervention to facilitate cognitive flexibility and regional brain volume regulation in rats exposed to VPA during gestation. It was found that exercise improved performance on extra-dimensional shifts of attention on a set-shifting task, which is indicative of improved cognitive flexibility. Exercise decreased frontal cortex volume in females, whereas in males exercise increased the ventral hippocampus. These findings suggest that aerobic exercise may be an effective intervention to counteract the altered development of prefrontal and hippocampal regions often observed in ASD.

20.
Health Sci Rep ; 7(7): e2233, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38966075

RESUMO

Background and Aims: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by a wide range of symptoms and challenges. While ASD is primarily associated with atypical social and communicative behaviors, increasing research has pointed towards the involvement of various brain regions, including the cerebellum. This review article aims to provide a comprehensive overview of the role of cerebellar lobules in ASD, highlighting recent findings and potential therapeutic implications. Methods: Using published articles found in PubMed, Scopus, and Google Scholar, we extracted pertinent data to complete this review work. We have searched for terms including anatomical insights, neuroimaging, neurobiological, and autism spectrum disorder. Results: The intricate relationship between the cerebellum and other brain regions linked to ASD has been highlighted by neurobiological research, which has shown abnormalities in neurotransmitter systems and cerebellar circuitry. The relevance of the cerebellum in the pathophysiology of ASD has been further highlighted by anatomical studies that have revealed evidence of cerebellar abnormalities, including changes in volume, morphology, and connectivity. Conclusion: Thorough knowledge of the cerebellum's function in ASD may lead to new understandings of the underlying mechanisms of the condition and make it easier to create interventions and treatments that are more specifically targeted at treating cerebellar dysfunction in ASD patients.

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