Structural modification of Schwann cells in the pancreatic islets of the dog.

In dog pancreatic islets, Schwann cells not only ensheath autonomic nerves but also have cytoplasmic processes that are contiguous with large expanses of the islet surface. These processes are interposed between the islet basal lamina and the endocrine parenchyma. This structural modification of Schwann cells may play a role in the neural control of islet function.