ACTH in the pigeon vestibular ganglion

Adrenocorticotropic hormone (ACTH) is a member of the opiocortin family of peptides. Within the central nervous system, ACTH-synthesizing neurons are generally considered to be located within the hypothalamus and are known to be involved in the neural circuitry underlying the integration of stress responses. We now report the existence of ACTH-positive perikarya within the pigeon vestibular ganglion. This result makes it likely that ACTH may act in other systems as a transmitter/modulator outside a stress-related context. Since the vestibular ganglia of mammals are known to be glutaminergic, the present data further extends possibility that ACTH is co-localized with glutamate.