Autism spectrum disorder (ASD) includes a range of neurodevelopmental disabilities characterized by social interaction deficits, communication impairments, and repetitive behaviors. Previous studies have shown that pro-inflammatory conditions play a key role in ASD. Despite this, how oxidative stress and inflammation may contribute to ASD-related behaviors is still poorly understood.
View Article and Find Full Text PDFIntroduction: Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental Q8 conditions characterized by deficits in social interaction/communication and restrictive/repetitive behaviors. Recent studies highlight the role of immune system dysfunction and inflammation in ASD pathophysiology. Indeed, elevated levels of pro-inflammatory cytokines were described in the brain and peripheral blood of ASD individuals.
View Article and Find Full Text PDFRecent findings show that effective integration of novel information in the brain requires coordinated processes of homo- and heterosynaptic plasticity. In this work, we hypothesize that activity-dependent remodeling of the peri-synaptic extracellular matrix (ECM) contributes to these processes. We show that clusters of the peri-synaptic ECM, recognized by CS56 antibody, emerge in response to sensory stimuli, showing temporal and spatial coincidence with dendritic spine plasticity.
View Article and Find Full Text PDFUnderstanding the neural basis of emotions is a critical step to uncover the biological substrates of neuropsychiatric disorders. To study this aspect in freely behaving mice, neuroscientists have relied on the observation of ethologically relevant bodily cues to infer the affective content of the subject, both in neutral conditions or in response to a stimulus. The best example of that is the widespread assessment of freezing in experiments testing both conditioned and unconditioned fear responses.
View Article and Find Full Text PDFAlzheimer's disease (AD) is characterized behaviorally by cognitive deterioration and emotional disruption, and neuropathologically by amyloid-β (A β) plaques, neurofibrillary tangles, and complement C3 (C3)-expressing neurotoxic, reactive astrocytes. We previously demonstrated that C3 + reactive astrocytes in the hippocampus and entorhinal cortex of AD patients express serine racemase (SR), which produces the N-methyl-D-aspartate receptor (NMDAR) co-agonist D-serine. We show here that C3 + reactive astrocytes express SR in the amygdala of AD patients and in an amyloid mouse model of familial AD (5xFAD).
View Article and Find Full Text PDFMounting evidence supports a key involvement of the chondroitin sulfate proteoglycans (CSPGs) NG2 and brevican (BCAN) in the regulation of axonal functions, including axon guidance, fasciculation, conductance, and myelination. Prior work suggested the possibility that these functions may, at least in part, be carried out by specialized CSPG structures surrounding axons, termed axonal coats. However, their existence remains controversial.
View Article and Find Full Text PDFSensory abnormalities are a common feature in autism spectrum disorders (ASDs). Tactile responsiveness is altered in autistic individuals, with hypo-responsiveness being associated with the severity of ASD core symptoms. Similarly, sensory abnormalities have been described in mice lacking ASD-associated genes.
View Article and Find Full Text PDFPostnatal development of the brain is characterized by sensitive windows during which, local circuitry are drastically reshaped by life experiences. These critical periods (CPs) occur at different time points for different brain functions, presenting redundant physiological changes in the underlying brain regions. Although circuits malleability during CPs provides a valuable window of opportunity for adaptive fine-tuning to the living environment, this aspect of neurodevelopment also represents a phase of increased vulnerability for the development of a variety of disorders.
View Article and Find Full Text PDFAbnormal tactile response is an integral feature of Autism Spectrum Disorders (ASDs), and hypo-responsiveness to tactile stimuli is often associated with the severity of ASDs core symptoms. Patients with Phelan-McDermid syndrome (PMS), caused by mutations in the SHANK3 gene, show ASD-like symptoms associated with aberrant tactile responses. The neural underpinnings of these abnormalities are still poorly understood.
View Article and Find Full Text PDFGrowing evidence points to a critical involvement of the extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Decreases of perineuronal nets (PNNs) and altered expression of chondroitin sulphate proteoglycans (CSPGs) in glial cells have been identified in several brain regions. GWAS data have identified several SZ vulnerability variants of genes encoding for ECM molecules.
View Article and Find Full Text PDFPerineuronal nets (PNNs) are extracellular matrix (ECM) structures that envelop neurons and regulate synaptic functions. Long thought to be stable structures, PNNs have been recently shown to respond dynamically during learning, potentially regulating the formation of new synapses. We postulated that PNNs vary during sleep, a period of active synaptic modification.
View Article and Find Full Text PDFAbnormal response to tactile stimulation, described as both hyper- and hypo-reactivity, is a common sensory impairment in multiple neuropsychiatric disorders. The neural bases of tactile sensitivity remain so far unknown. In the last years, animal studies have proven to be useful for shedding light on the cellular and molecular mechanism underlying sensory impairments.
View Article and Find Full Text PDFOverreactivity and defensive behaviors in response to tactile stimuli are common symptoms in autism spectrum disorder (ASD) patients. Similarly, somatosensory hypersensitivity has also been described in mice lacking ASD-associated genes such as (fragile X mental retardation protein 1). knock-out mice also show reduced functional connectivity between sensory cortical areas, which may represent an endogenous biomarker for their hypersensitivity.
View Article and Find Full Text PDFGrowing evidence points to synaptic pathology as a core component of the pathophysiology of schizophrenia (SZ). Significant reductions of dendritic spine density and altered expression of their structural and molecular components have been reported in several brain regions, suggesting a deficit of synaptic plasticity. Regulation of synaptic plasticity is a complex process, one that requires not only interactions between pre- and post-synaptic terminals, but also glial cells and the extracellular matrix (ECM).
View Article and Find Full Text PDFMicroRNAs (miRNAs) are known to mediate post-transcriptional gene regulation, but their role in postnatal brain development is still poorly explored. We show that the expression of many miRNAs is dramatically regulated during functional maturation of the mouse visual cortex with miR-132/212 family being one of the top upregulated miRNAs. Age-downregulated transcripts are significantly enriched in miR-132/miR-212 putative targets and in genes upregulated in miR-132/212 null mice.
View Article and Find Full Text PDFSince Ebbinghaus' classical work on oblivion and saving effects, we know that declarative memories may become at first spontaneously irretrievable and only subsequently completely extinguished. Recently, this time-dependent path toward memory-trace loss has been shown to correlate with different patterns of brain activation. Environmental enrichment (EE) enhances learning and memory and affects system memory consolidation.
View Article and Find Full Text PDFSocial behavior is evolutionary conserved, and is thought to be evolved since it increased reproductive and survival fitness of living species. In humans, disturbances of social behavior are a peculiar pathological trait of neurodevelopmental disorders, namely autism spectrum disorder (ASD). ASD is defined by deficits in two core domains (social interaction/communication and repetitive/restrictive behaviors), which emerge during early postnatal development.
View Article and Find Full Text PDFBackground: CDKL5 (cyclin-dependent kinase-like 5) is mutated in many severe neurodevelopmental disorders, including atypical Rett syndrome. CDKL5 was shown to interact with synaptic proteins, but an in vivo analysis of the role of CDKL5 in dendritic spine dynamics and synaptic molecular organization is still lacking.
Methods: In vivo two-photon microscopy of the somatosensory cortex of Cdkl5(-/y) mice was applied to monitor structural dynamics of dendritic spines.