Summary
International Symposium on Nonlinear Theory and its Applications
2008
Session Number:B4L-B
Session:
Number:B4L-B5
Chaos and bifurcation in a stochastic model of the calyx of Held
Michael Small, Hugh Robinson,
pp.-
Publication Date:2008/9/7
Online ISSN:2188-5079
Summary:
The calyx of Held is a giant glutamatergic synapse in the auditory system. Short-term plasticity (either facilitation and depression) have been observed experimentally and in proposed biophysical models of the system. Because of the large number of discrete release site for the vesicles (which in turn drive the gating process at the synapse), the random process of vesicle release is modelled as a continuous differential equation. We propose a new stochastic discrete model of vesicle release and show that even for large pools of release sites, the short-term plasticity of the system deviates from the continuous model as the number of available docked vesicles decreases. We compare results of this new stochastic-discrete biophysical model with the previous deterministic-contiunous biophysical model and with models derived from synaptic transmission data obtained from the rat cortex.