Bistability in pulse propagation in networks of excitatory and inhibitory populations

We study the propagation of traveling solitary pulses in one-dimensional ne tworks of excitatory and inhibitory integrate-and-fire neurons. Slow pulses , during which inhibitory cells fire well before neighboring excitatory cel ls, can propagate along the network at intermediate inhibition levels. At h igher levels, they destabilize via a Hopf bifurcation. There is a bistable parameter regime in which both fast and slow pulses can propagate. Lurching pulses with spatiotemporal periodicity can propagate in regimes for which continuous pulses do not exist.