Project description:In this study we hypothesize that early life stress perturbs the normal function of microglia in the developing hippocampus and that this effect is responsible for the ability of early life tress to disrupt normal synaptic maturation, myelination, and axonal growth in the developing hippocampus. To test this hypothesis we used the mouse immune panel from NanoString in order to identify immune-related genes whose expression is modified by BDS, a mouse model of early life stress, in microglia isolated from the hippocampus of 14-day old male pups. This project is part of a manuscript that is currently under preparation (Delpech J.C. et al. Early life stress perturbs the maturation of microglia in the developing hippocampus, Brain, Behavior and Immunity, 2016)
Project description:In this study we hypothesize that early life stress perturbs the normal function of microglial in the developing hippocampus and that this effect is responsible for the ability of early life tress to disrupt normal synaptic maturation, myelination, and axonal growth in the developing hippocampus. To test this hypothesis we used the mouse immune panel from NanoString in order to identify immune-related genes whose expression is modified by BDS, a mouse model of early life stress, in microglia isolated from the hippocampus of 28-day old male pups. This project is part of a manuscript that is currently under preparation (Delpech J.C. et al. Early life stress perturbs the maturation of microglia in the developing hippocampus, Brain, Behavior and Immunity, 2016)
Project description:The goal of this project was to identify genes whose expression is modified by age in microglia isolated from the hippocampus of 14 and 28-day old control mice (i.e. normally developing mice). To accomplish this we used two independent cohorts of control mice and identified a list of 76 genes that were significantly regulated by age (p< 0.05) in both cohorts. Data for cohort 1 were extracted from gene expression of P14 and P28 control mice available in the BDS-P14-male series (GSE81036) and BDS-P28-male series (GSE81037). Data for cohort 2 are available in this series. These data are summarized also in Table S3 in Delpech J.C. et al. Early life stress perturbs the maturation of microglial cells in the developing hippocampus, Brain, Behavior and Immunity, 2016 (in preparation).
Project description:The goal of this project was to assess the effects of two paradigms of early life stress on microglial gene expression in the developing hippocampus of 17-day old mice. Sixty thousands microglia were isolated from the hippocampus of 17-day old mice pups exposed to control (CTL), limited bedding (LB) or unpredictable postnatal stress (UPS) conditions and were processed to assess gene expression using the mouse Glia panel (Nanostring, Cat # XT-Mm Glial profiling CSO).
Project description:Sleep supports lifelong brain health and cognition. Sleep loss in early life can drive lasting changes in adult behavior, indicating sleep plays a distinct but poorly understood role supporting brain development. We systematically examined the molecular and behavioral adaptations and synaptic consequences of acute sleep deprivation (SD) in developing and adult mice. Developing mice lack robust adaptations to SD, exacerbating cognitive deficits. Synapse proteome and phosphoproteome analysis revealed profound vulnerability to SD in developing mice, including immediate impacts on synaptogenesis and key aspects of brain development. With maturation, a unified biochemical effect of sleep on synapses emerges, together with robust adaptations and resilience to SD. Our findings show sleep plays a distinct role in early life supporting synapse development, transitioning to homeostatic functions with maturation.
Project description:Neuron-microglia interactions dictate the development of neuronal circuits in the brain. However, the factors that support and broadly regulate these processes across developmental stages are largely unknown. Here, we find that IL34, a neuron-derived cytokine, is upregulated in development and plays a critical role in supporting and maintaining neuroprotective, mature microglia in the anterior cingulate cortex (ACC) of mice. We show that IL34 mRNA and protein is upregulated in neurons in the second week of postnatal life and that this increase coincides with increases in microglia number and expression of mature, homeostatic markers, e.g., TMEM119. We also found that IL34 mRNA is higher in excitatory (compared to inhibitory) neurons. Global genetic KO of IL34 reduced microglia numbers and prevented the functional maturation of microglia, and excitatory-neuron specific KO of IL34 similarly impacted microglia and increased aberrant microglial phagocytosis of excitatory thalamocortical synapses in the ACC. Acute, low dose blocking of IL34 at postnatal day (P)15 in mice decreased microglial TMEM119 protein and also increased microglial phagocytosis of excitatory thalamocortical synapses during an inappropriate time in development. In contrast, viral overexpression of IL34 early in life (P1-P8) caused early maturation of microglia and prevented microglial phagocytosis of thalamocortical synapses during the appropriate neurodevelopmental refinement window. Taken together, these findings establish IL34 as a key regulator of neuron microglia crosstalk in postnatal brain development, controlling both microglial maturation and synapse engulfment.