Simulation and Analysis of Synaptic Transmission in Hippocampal Dentate Gyrus Granule Cells

M.Sc. 1995, Department of Physiology and Institute of Biomedical Engineering, University of Toronto

Using measurements from actual cells, a stochastic algorithm was developed and used to generate random rat dentate gyrus (DG) granule cell shapes which as a family look like a population of real neurons. This addresses the natural geometric variation of DG cells found in vivo and overcomes the undersampling problem usually found in morphologically realistic modelling studies. This geometric data set was used to generate compartmental models and to compute passive electrical parameters. A simple local sensitivity analysis method to ascertain the dependence of simulation results on parameters of interest is derived.

This model was used to simulate the response to synapses within the dendritic trees and somas of different DG granule cell shapes. Simulation results regarding the effects of tree shape, spines, passive parameters, and synaptic location on the dendritic and soma response are presented. The dependence of the results on simulation parameters is ascertained using the sensitivity analysis. Comparisons are made between the simulated responses and actual responses made from rat DG granule cells.