Speaker: Peter Rowat,
Institute for Neural Computation,
UCSD

Title: Spike Time Variability

Abstract: It is over 50 years since Hodgkin and Huxley published their well-known model of the squid axon, which today is the primary foundation-stone of computational neuroscience. If one takes into account the intrinsic noise due to Na- and K- ion channels opening and closing when a neuron is firing, one can get very high variability in the spike times, with coefficient of variation well above 1 for some values of the injected current. This is without any synaptic inputs. I find this very surprising, since many people have looked at the effects of noise in the Hodgkin-Huxley equations but this high variability had never been observed or appreciated before. I'll describe the results and the underlying dynamical mechanisms, and discuss the significance of this result to present efforts to understand the apparent high spike time variability seen in cortex and elsewhere.