A model network with pulsed external inputs reproduces the similarity of the responses for two types of excitatory neurons.

(A) Conceptual cartoon illustrating key model features, including inhibitory neurons (blue) and two types of excitatory neurons (green/A and magenta/B), with excitatory external inputs (“LGN”, orange) limited to one excitatory type (green/A). Intracluster and intercluster connection probabilities are parameterized by Pin and Pout, respectively. (B) Simulated membrane potential responses for the two types of excitatory model neurons (green/A and magenta/B) in response to a brief (100 ms, black horizontal bar) increase in the external input (increased rate of the Poisson pulse trains) for multiple combinations of intracluster and intercluster connection probabilities, each ranging between 0.0 and 0.5. For clarity, simulation results for 200 of the 1000 neurons of each excitatory type are plotted. (C) The connection probability combination of Pin = 0.1 and Pout = 0.25 best reproduces the experimentally observed persistent activity and the similarity of the type A (green) and the type B (magenta) response to brief external inputs.