Resumen
Let f (·, ): be given so that f (0, )=0 and f (x, )=(1+) x+ax2+bx3+o (x3) as x0. We characterize those small values of >0 and for which there are periodic solutions of periods approximately with k of the following system arising from a network of neurons The periodic solutions are synchronized if k is even and phase-locked if k is odd. We show that, as 0, these periodic solutions approach square waves if a=0 and b<0, and pulses if a=0 and b>0 or if a0.