EFFECTS OF PHYSOSTIGMINE ON SYNAPTIC TRANSMISSION IN INFERIOR MESENTERIC GANGLION OF GUINEA-PIGS

Abstract

1. Synaptic potentials were recorded with intracellular electrodes from cells in the inferior mesenteric ganglion of the guinea-pig.2. Half-widths of the synaptic potentials recorded fell into two groups: type L cells had long synaptic potentials (11.6-15.2 msec) and low thresholds (14.6 mV mean), type S cells had short synaptic potentials (6.1-9.3 msec) and high thresholds (29.9 mV mean).3. Physostigmine (1.2 x 10(-6)M) caused a significant increase in the half-width of both types of synaptic potential.4. Physostigmine caused a significant increase in the half-width of spontaneous synaptic potentials and an increase in their amplitude.5. Repetitive preganglionic stimulation, in the presence..