Coexistence of immunoreactivities for glutamate decarboxylase and tyrosine hydroxylase in some neurons in the periglomerular region of the rat main olfactory bulb: possible coexistence of gamma-aminobutyric acid (GABA) and dopamine.

The coexistence of immunoreactivities for glutamate decarboxylase (GAD) and tyrosine hydroxylase (TH) was revealed in some neurons in the periglomerular region and in the superficial part of the external plexiform layer of the rat main olfactory bulb. In neurons showing the immunoreactivity for either GAD or TH, about 10-55% showed both immunoreactivities.