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NJIT Mathematical Biology Seminar

Tuesday, March 30, 2010, 2:30pm
Cullimore Hall 611
New Jersey Institute of Technology

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Subthreshold Oscillations in Hippocampal Interneurons

Darrell Haufler

Center for Molecular and Behavioral Neuroscience, Rutgers University

A class of hippocampal interneurons in CA1, bordering the lacunosum-moleculare and radiatum hippocampal layers (the LM/R cell), has been shown to exhibit membrane potential oscillations (MPOs) subthreshold to action potential generation. MPOs occur at theta frequency (4-12 Hz) and are of interest because of their putative role in promoting network level theta activity. MPOs arise without synaptic input suggesting that they originate through interactions in the cell^Rs repertoire of currents.

To investigate the generation of MPOs we develop a single compartment model of the LM/R cell based on the physiological characterization of its currents. We show that MPOs depend only linearly on individual currents for a given level of depolarization and that they arise through a process known as critical slowing down. Finally, the magnitudes of the A-type potassium and persistent sodium currents are shown to be of particular importance in shaping MPOs in this cell type.