Some properties of spontaneous excitatory junction potentials recorded from arterioles of guinea‐pigs.

Abstract

Spontaneous excitatory junction potentials were recorded from electrically short segments of arterioles taken from the intestinal submucosa of guinea pigs. Histograms of the amplitudes of these spontaneous potentials were unimodal; their amplitudes often corresponded with the amplitudes of the smallest evoked potentials recorded from the same preparation. The time courses of spontaneous and evoked potentials were very similar; evoked potentials apparently are made up by the simultaneous occurrence of several spontaneous potentials. The mean quantal content of evoked potentials was always lower than the number of varicosities present in the preparations. During neuromuscular transmission, transmitter may be released at relatively few sites throughout the ground plexus for each nerve impulse.