ABSTRACT
The trajectory of the membrane potential in a cortical neuron is very noisy. The sequence of events which generate this variability is summarized in Figure 6.1. Unlike the input of a sensory receptor, that of a cortical cell is complex and not completely controllable, or even knowable, in experiments. The process of generating the membrane potential signal begins with a set of effectively stochastic presynaptic action potential trains converging on some 104 synaptic terminals, distributed over the dendritic tree of the neuron. Each of these spike trains drives a highly unreliable and stochastic process of transmitter release at each terminal. The released transmitter then opens ion channels whose opening and closing behaves exactly like a stochastic (Markov) process, as described in detail in the chapter by Alan Hawkes. As the membrane potential then changes, other Markovian ion channels whose transition 1-58488-362-6/04/$0.00+$l .50
