Abstract
Effects of 5-hydroxytryptamine, sodium picrate, caerulein and pentagastrin on the electrical activities obtained from Auerbach's plexus in the guinea pig ileum were investigated. The drugs used increased the spike frequency and increase of the spike frequency induced was inhibited by morphine but not by atropine and hexamethonium. The muscle spikes obtained simultaneously were inhibited by atropine. These facts indicate that the drugs used stimulate Auerbach's plexus and accelerate the acetylcholine release from the cholinergic post-ganglinoic nerve endings. The sites of action of morphine are also discussed.
