Search results for "hippocampus"

Heterozygous Variants in KDM4B Lead to Global Developmental Delay and Neuroanatomical Defects

2020

International audience; KDM4B is a lysine-specific demethylase with a preferential activity on H3K9 tri/di-methylation (H3K9me3/2)-modified histones. H3K9 tri/di-demethylation is an important epigenetic mechanism responsible for silencing of gene expression in animal development and cancer. However, the role of KDM4B on human development is still poorly characterized. Through international data sharing, we gathered a cohort of nine individuals with mono-allelic de novo or inherited variants in KDM4B. All individuals presented with dysmorphic features and global developmental delay (GDD) with language and motor skills most affected. Three individuals had a history of seizures, and four had a…

Social stress during adolescence activates long-term microglia inflammation insult in reward processing nuclei

2018

The experience of social stress during adolescence is associated with higher vulnerability to drug use. Increases in the acquisition of cocaine self-administration, in the escalation of cocaine-seeking behavior, and in the conditioned rewarding effects of cocaine have been observed in rodents exposed to repeated social defeat (RSD). In addition, prolonged or severe stress induces a proinflammatory state with microglial activation and increased cytokine production. The aim of the present work was to describe the long-term effects induced by RSD during adolescence on the neuroinflammatory response and synaptic structure by evaluating different glial and neuronal markers. In addition to an inc…

Spatial learning and long-term memory impairments in RasGrf1 KO, Pttg1 KO, and double KO mice

2018

© 2018 The Authors.

Oligodendrocytes support axonal transport and maintenance via exosome secretion

2020

Neurons extend long axons that require maintenance and are susceptible to degeneration. Long-term integrity of axons depends on intrinsic mechanisms including axonal transport and extrinsic support from adjacent glial cells. The mechanisms of support provided by myelinating oligodendrocytes to underlying axons are only partly understood. Oligodendrocytes release extracellular vesicles (EVs) with properties of exosomes, which upon delivery to neurons improve neuronal viability in vitro. Here, we show that oligodendroglial exosome secretion is impaired in 2 mouse mutants exhibiting secondary axonal degeneration due to oligodendrocyte-specific gene defects. Wild-type oligodendroglial exosomes …

Proteomic Analysis of Brain Region and Sex-Specific Synaptic Protein Expression in the Adult Mouse Brain

2020

Genetic disruption of synaptic proteins results in a whole variety of human neuropsychiatric disorders including intellectual disability, schizophrenia or autism spectrum disorder (ASD). In a wide range of these so-called synaptopathies a sex bias in prevalence and clinical course has been reported. Using an unbiased proteomic approach, we analyzed the proteome at the interaction site of the pre- and postsynaptic compartment, in the prefrontal cortex, hippocampus, striatum and cerebellum of male and female adult C57BL/6J mice. We were able to reveal a specific repertoire of synaptic proteins in different brain areas as it has been implied before. Additionally, we found a region-specific set…

Differential Impact of Ad Libitum or Intermittent High-Fat Diets on Bingeing Ethanol-Mediated Behaviors

2019

Background: Dietary factors have significant effects on the brain, modulating mood, anxiety, motivation and cognition. To date, no attention has been paid to the consequences that the combination of ethanol (EtOH) and a high-fat diet (HFD) have on learning and mood disorders during adolescence. The aim of the present work was to evaluate the biochemical and behavioral consequences of ethanol binge drinking and an HFD consumption in adolescent mice. Methods: Animals received either a standard diet or an HFD (ad libitum vs. binge pattern) in combination with ethanol binge drinking and were evaluated in anxiety and memory. The metabolic profile and gene expression of leptin receptors and clock…

Hyperammonemia alters the mismatch negativity in the auditory evoked potential by altering functional connectivity and neurotransmission

2020

Minimal hepatic encephalopathy (MHE) is a neuropsychiatric syndrome produced by central nervous system dysfunction subsequent to liver disease. Hyperammonemia and inflammation act synergistically to alter neurotransmission, leading to the cognitive and motor alterations in MHE, which are reproduced in rat models of chronic hyperammonemia. Patients with MHE show altered functional connectivity in different neural networks and a reduced response in the cognitive potential mismatch negativity (MMN), which correlates with attention deficits. The mechanisms by which MMN is altered in MHE remain unknown. The objectives of this work are as follows: To assess if rats with chronic hyperammonemia rep…

Anxiolytic effects of muscarinic acetylcholine receptors agonist oxotremorine in chronically stressed rats and related changes in BDNF and FGF2 level…

2017

Rationale: In depressive disorders, one of the mechanisms proposed for antidepressant drugs is the enhancement of synaptic plasticity in the hippocampus and cerebral cortex. Previously, we showed that the muscarinic acetylcholine receptor (mAChR) agonist oxotremorine (Oxo) increases neuronal plasticity in hippocampal neurons via FGFR1 transactivation. Objectives: Here, we aimed to explore (a) whether Oxo exerts anxiolytic effect in the rat model of anxiety-depression-like behavior induced by chronic restraint stress (CRS), and (b) if the anxiolytic effect of Oxo is associated with the modulation of neurotrophic factors, brain-derived neurotrophic factor (BDNF) and fibroblast growth factor-2…

Hemisphere-dependent endocannabinoid system activity in prefrontal cortex and hippocampus of the Flinders Sensitive Line rodent model of depression

2019

Altered endocannabinoid (eCB) signaling is suggested as an important contributor to the pathophysiology of depression. To further elucidate this, we conducted a study using a genetic rat model of depression, the Flinders Sensitive Line (FSL), and their controls, the Flinders Resistant Line (FRL) rats. Plasma, right and left prefrontal cortex, and hippocampus were isolated from FSL and FRL rats. We analyzed each region for the eCB anandamide (AEA) and 2-arachidonoylglycerol (2-AG) levels by liquid chromatography/multiple reaction monitoring (LC/MRM), mRNA and protein levels of the cannabinoid type 1 receptor (CB1R), fatty acid amide hydrolase (FAAH) and monoacyl glycerol lipase (MAGL) by rea…

2018

In mammalian species, including humans, the hippocampal dentate gyrus (DG) is a primary region of adult neurogenesis. Aberrant adult hippocampal neurogenesis is associated with neurological pathologies. Understanding the cellular mechanisms controlling adult hippocampal neurogenesis is expected to open new therapeutic strategies for mental disorders. Microglia is intimately associated with neural progenitor cells in the hippocampal DG and has been implicated, under varying experimental conditions, in the control of the proliferation, differentiation and survival of neural precursor cells. But the underlying mechanisms remain poorly defined. Using fluorescent in situ hybridization we show th…