Project description:During brain development, layer 5 neurons distributed across most areas of the neocortex innervate the pontine nuclei (basilar pons) by the initiation and extension of collateral branches interstitially along their corticospinally extending axons. We used microarrays to compare gene expression profiles of brain areas that were projected (pontine nucleus, superior colliculus) and were not projected (cerebellum, olfactory bulb) by axon collaterals from the corticospinal tract in order to understand genetic programs that regulate axon collaterals formation.
Project description:We purified the differentiating ciliated cells from E17.5 mouse lungs and used Affymetrix microarrays to obtain their gene expression profiles.
Project description:Microglia colonize the brain parenchyma at early stages of development and accumulate in specific regions where they actively participate in cell death, angiogenesis, neurogenesis and synapse elimination. A recurring feature of embryonic microglial distribution is their association with developing axon tracts which, together with in vitro data, supports the idea of a physiological role for microglia in neurite development. Yet the demonstration of this role of microglia is still lacking. Here, we have studied the consequences of microglial dysfunction on the formation of the corpus callosum, the largest connective structure in the mammalian brain, which shows consistent microglial accumulation during development. We studied two models of microglial dysfunction: the loss-of-function of DAP12, a key microglial-specific signaling molecule, and a model of maternal inflammation by peritoneal injection of LPS at E15.5. We performed transcriptional profiling of maternally inflamed and Dap12-mutant microglia at E17.5. We found that both treatments principally down-regulated genes involved in nervous system development and function, particularly in neurite formation. We then analyzed the functional consequences of these microglial dysfunctions on the formation of the corpus callosum. We also took advantage of the Pu.1-/- mouse line, which is devoid of microglia. We now show that all three models of altered microglial activity resulted in the same defasciculation phenotype. Our study demonstrates that microglia are actively involved in the fasciculation of corpus callosum axons. To investigate possible roles for microglial during brain development, we challenged microglial function by two complementary approaches. First, we induced maternal inflammation by peritoneal injection of LPS into pregnant dams. Next, we analyzed the consequences of a loss of function of DAP12, a signaling molecule specifically expressed in microglia that is crucial for several aspects of microglia biology (references in Wakselman et al., 2008). We compared the gene expression profiles of microglia from control, maternally-inflamed by LPS (MI), and Dap12-mutated embryos. We isolated RNA from FACS sorted maternally inflamed (by LPS) and Dap12-mutant microglia at E17.5 pooled per pregnant dam; as a control we included PBS treated and untreated (UT) microglia. We compared gene expression between maternally inflamed microlgia (PBSvsLPS) and DAP12-mutant microglia (UTvsDAP12KO).
Project description:Assessed steady-state transcription in whole brain and two more specific brain regions. Studied the impact of strain genetic background on expression levels. In addition, we also studied the effects of acute clozapine exposure on gene expression in mouse brain.
Project description:This SuperSeries is composed of the following subset Series: GSE24829: Gene expression data from striatal regions of MPTP-intoxicated mouse brain by acupuncture GSE24830: Gene expression data from cervical spinal cord regions of MPTP-intoxicated mouse by acupuncture Refer to individual Series