Fig. 3.

Conservation of response dynamic range. The spike rate of the model neuron is plotted as a function of the average input spike rate. A, Simulations with 300 excitatory inputs and 300 inhibitory inputs; parameters are the same as in Figure 2, F and G (barrier height, 15 steps; τ = 20 msec). The balanced excitation–inhibition model produces a response that is approximately the same as one of its many inputs. B, Simulations with 600 excitatory and inhibitory inputs. Open symbols and dashed curve show the response obtained using the same model parameters as in A. Solid symbolsand curve show the response when the barrier height is increased to 25 steps. These simulations suggest that a small hyperpolarization could be applied to enforce a unity gain input–output relationship when the number of active inputs is large.