A nonuniform density of subthreshold, rapidly inactivating potassium channels regulates signal propagation in the dendrites of CA1 pyramidal neurons of the hippocampus. This nonuniform distribution (with higher expression in the dendrites than in the soma) means that the electrical properties of the dendrites are markedly different from those of the soma. Incoming synaptic signals are shaped by the activity of these channels, and action potentials, once initiated in the axon, progressively decrease in amplitude as they propagate back into the dendrites. By combining patch clamp recording in brain slices of the hippocampus with molecular biology techniques, the Molecular Neurophysiology and Biophysics Unit investigates the electrophysiological properties and molecular nature of the voltage-gated channels expressed in CA1 dendrites, how their expression is regulated, and their role in synaptic integration and plasticity.

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Support Year
1
Fiscal Year
2003
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Indirect Cost
Name
U.S. National Inst/Child Hlth/Human Dev
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Country
United States
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Kim, Jinhyun; Jung, Sung-Cherl; Clemens, Ann M et al. (2007) Regulation of dendritic excitability by activity-dependent trafficking of the A-type K+ channel subunit Kv4.2 in hippocampal neurons. Neuron 54:933-47
Kwon, Oh-Bin; Longart, Marines; Vullhorst, Detlef et al. (2005) Neuregulin-1 reverses long-term potentiation at CA1 hippocampal synapses. J Neurosci 25:9378-83
Kim, Jinhyun; Wei, Dong-Sheng; Hoffman, Dax A (2005) Kv4 potassium channel subunits control action potential repolarization and frequency-dependent broadening in rat hippocampal CA1 pyramidal neurones. J Physiol 569:41-57
Krestel, Heinz E; Mihaljevic, Andre L A; Hoffman, Dax A et al. (2004) Neuronal co-expression of EGFP and beta-galactosidase in mice causes neuropathology and premature death. Neurobiol Dis 17:310-8
Johnston, Daniel; Christie, Brian R; Frick, Andreas et al. (2003) Active dendrites, potassium channels and synaptic plasticity. Philos Trans R Soc Lond B Biol Sci 358:667-74