On the Generation of Subthreshold Membrane Potential Fluctuations in Hippocampal Ca1 Interneurons
Year: 2009
Type: dissertation
Abstract: 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’s repertoire of currents.\nTo investigate the generation of MPOs we develop a single compartment model of the cell based on the physiological characterization of its currents. The model includes both deterministic current models and white noise. Our analysis allows for a complete characterization of the cell’s dynamics over the subthreshold range and shows that MPOs arise through the interaction between current dynamics and system noise. We find that MPOs show a particular dependency on the A-type potassium and persistent sodium current magnitudes.
Source: TSpace (University of Toronto)
Author: Darrell Haufler
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W15362355