Propagating activity patterns in large-scale inhibitory neuronal networks

The propagation of activity is studied in a spatially structured network model of γ-aminobutyric acid-containing (GABAergic) neurons exhibiting postinhibitory rebound. In contrast to excitatory-coupled networks, recruitment spreads very slowly because cells fire only after the postsynaptic conductance decays, and with two possible propagation models. If the connection strength decreases monotonically with distance (on-center), then propagation occurs in a discontinuous manner. If the self- and nearby connections are absent reversal potential can result in depolarization- mediated eaves that are 25 times faster. Functional and developmental roles for these behaviors and implications for thalamic circuitry are suggested.