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NJIT Mathematical Biology Seminar

Tuesday, October 5, 2010, 2:30pm
Cullimore Hall 611
New Jersey Institute of Technology

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The effect of periodic and non-periodic inputs on firing rate resonance in a stellate cell model

Dongwook Kim

Department of Mathematical Sciences, NJIT

Various neuron types exhibit sub-threshold and firing frequency resonance in which the sub-threshold membrane potential or firing frequency responses to periodic inputs (such as sinusoidal) peak at a preferred frequency (or frequencies). Previous experimental work has shown that medial entorhinal cortex layer II stellate cells (SCs) exhibit sub-threshold and firing frequency resonance in the theta frequency band (4 - 10 Hz). In this project we seek to understand the biophysical and dynamic mechanism underlying these phenomena, and how sub-threshold and firing frequency resonance are related. We studied the effects of sinusoidal current and synaptic conductance inputs at various frequencies, at various noise levels, on the supra-threshold dynamics on a SC model. For current inputs, our results show that while the SC model exhibits a single frequency preference peak (in the theta band) for low sinusoidal input levels, it exhibits three preferred frequency peaks for larger input levels. These additional peaks occur at frequencies that are roughly a multiple of the "theta" one. For synaptic conductance inputs, we observe an additional peak in the signal gain which occurs at a much higher frequency (in the high gamma band). These findings depart from the linear prediction.