Structure of the myenteric plexus in the sphincters of cat gastro-intestinal tract. VI. Axonal profiles, axonal varicosities, synapses and other membrane differentiations.

Axonal varicosities of adrenergic, cholinergic and p-ergic types are observed in the myenteric plexus of cat lower esophageal, pyloric and ileo-caecal sphincters. In addition to them, there are varicosities, which cannot be attributed to the above types. The synaptic contacts in the myenteric ganglia manifest a great variety. The three main types of axonal varicosities appear as presynaptic part. Axodendritic synapses predominate. Very frequent findings are the symmetric membrane differentiations between the perikarya, dendrites and axonal profiles, as well as membrane junctions between the nerve and glial cells.