Intrinsic Membrane Properties Vary Across Cortical Regions

Main Category: Neurology / Neuroscience
Article Date: 18 Dec 2008 - 3:00 PDT

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A neuron's function is determined by many factors, including its connections, morphology, and molecular makeup, and these characteristics, together with anatomical positions, are used to draw ever finer distinctions between neuronal classes. Miller and colleagues have found that expression of YFP under control of the Thy-1 promoter labels ~25% of pyramidal neurons in layer 5 of cortex. The authors now report that although YFP-labeled cells present in primary motor and sensory cortices have similar morphology, projections (in the pyramidal tract), and transcriptional sets, they respond differently to sustained current injection. Cells in sensory cortex fired at a constant rate upon current injection, whereas cells in motor cortex exhibited delayed and then accelerating spiking. These differences were attributed to expression of voltage-dependent, slowly inactivating outward currents mediated by potassium Kv1 channels in motor cortex. Such differences in intrinsic membrane properties are likely to contribute to the functional specification of cortical regions.

Authors:
Mark N. Miller, Benjamin W. Okaty, and Sacha B. Nelson

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Source:
Sara Harris
Society for Neuroscience