Fine structure of axons associated with the salivary apparatus of the cockroach, Nauphoeta cinerea.

Previous studies have shown that the neurotransmitter at the salivary gland of the cockroach is probably dopamine. An ultrastructural study of the innervation of these glands was made. It was concluded that there are two types of axon present designated type A and type B. Type A axons possess small agranular eliptical vesicles and large granular vesicles, whereas type B possess only large granular vesicles of larger diameter than those found in type A. The relationship of these types of axon to the cells of the acini is discussed. It is concluded that type A axons are catecholaminergic.