Cholinergic innervation of the simian oxyntic gastric mucosa.

The innervation of the oxyntic gastric mucosa was studied by light and electron microscopy in the rhesus monkey. An abundant net of acetylcholinesterase-positive nerves was seen in the lamina propria, with many slender fibers noted close to the basal lamina of the glands. Electron microscopic observation disclosed the presence of nerve fibers containing axons and varicosities in the lamina propria, often in very close proximity to the epithelial glandular cells. Nerve endings partly enveloped by a Schwann cell were occasionally seen in direct contact with a parietal cell.