Some properties of excitatory junction currents recorded from submucosal arterioles of guinea-pig ileum.

Excitatory junction potentials and excitatory junction currents have been recorded from short segments of arterioles taken from the submucosa of guinea-pig small intestine. Excitatory junction currents reached their peak amplitudes by 20 ms and then decayed, with a time course that could be described by a single exponential (mean time constant of decay approximately 50 ms). The null potential for excitatory junction currents obtained by extrapolation was near 0 mV. The time course of excitatory junction currents failed to show voltage sensitivity. Spontaneous excitatory junction currents had the same time course as evoked currents; the amplitudes of spontaneous currents were less than an order of magnitude different from that of evoked currents.