INVESTIGATION OF CENTRAL AUDITORY NUCLEI IN THE BUDGERIGAR WITH CYTOCHROME-OXIDASE HISTOCHEMISTRY

Cytochrome oxidase (CO) histochemistry was used to study the organization of central auditory structures in the budgerigar (Melopsittacus undulatus). In contrast to prior studies9 in birds showing that acetylcholinesterase staining is most intense within hindbrain auditory structures CO staining was prominent at all levels of the auditory pathway including the thalamus (i.e. nucleus ovoidalis) and primary telencephalic auditory area (Field 'L'). Furthermore, CO staining clearly distinguishes the boundaries of Field 'L' from adjacent portions of the neostriatum intermedium pars dorsolateralis2,3 which do not receive input from the auditory thalamus. Thus CO staining can be used as a marker for distinguishing auditory and non-auditory portions of the avian telencephalon. © 1990.