Project description:Molecular mechanisms controlling specification and differentiation of distinct neuron subtypes in the cerebral cortex are not well understood. Corticothalamic projection neurons (CThPN) are a diverse set of neurons, critical for function of the neocortex, but little is known about the molecular mechansims controlling their development. We used microarrays to detail CThPN gene expression at 3 developmental time points. We then compared CThPN gene expression, with the gene expression of other neuron subtypes in the cerebral cortex at the same stages (previously described in Arlotta et a., 2005) CThPN were retrogradely label with fluorescent microespheres injected into the thalamus, and were FACS purified at 3 developmental stages for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Molecular mechanisms over differentiation and differential axonal targeting of distinct neuron subtypes in the cerebral cortex are beginning to be elucidated. These studies have focused on controls that specifically distinguish one subtype of neocortical projection neurons, e.g. corticospinal motor neurons (CSMN), from closely related corticothalamic projection neurons (CThPN) or intracortical callosal projection neurons (CPN). CSMN are located in layer V of the neocortex and make synaptic connections to motor output circuitry in the spinal cord and brainstem. CSMN axons form the corticospinal tract (CST), which is the major motor output pathway from the motor cortex and critically controls voluntary movement. CSMN somatotopically and precisely target specific segments along the rostrocaudal axis of the spinal cord, the molecular basis for which remains unknown. We used microarrays to examine gene expression differences between two CSMN subpopulations that target different levels of the spinal cord - CSMN-C (which extend axons to the brainstem and cervical spinal cord) and CSMN-L (which preferrrentially extend axons to the thoracic and lumbar spinal cord). We compared CSMN-C vs CSMN-L gene expression at 3 critical developmental time points (previously described in Arlotta et a., 2005)
Project description:Molecular mechanisms controlling specification and differentiation of distinct neuron subtypes in the cerebral cortex are not well understood. Corticothalamic projection neurons (CThPN) are a diverse set of neurons, critical for function of the neocortex, but little is known about the molecular mechansims controlling their development. We used microarrays to detail CThPN gene expression at 3 developmental time points. We then compared CThPN gene expression, with the gene expression of other neuron subtypes in the cerebral cortex at the same stages (previously described in Arlotta et a., 2005)
Project description:We use comprehensive and unsupervised transcriptome analyses to provide molecular classifications of sensory neurons in the mouse geniculate ganglion. 96 neurons were isolated on a C1 Fluodigm chip, underwent RNA-Seq, and iteratively clustered into sub-classes.
