title: Distribution of GABAergic perikarya and terminals in the centers of the higher auditory pathway of the chicken.
abstract: The distribution of presumed GABAergic neurons and axon terminals in nuclei of the higher auditory pathway of the chicken was investigated by immunocyto-chemical methods employing antisera to the rate-limiting enzyme of GABA synthesis, glutamic acid decarboxylase, and to GABA. In the mesencephalic auditory center (MLD) about 20% of the cells reveal immunoreactivity. In contrast, the thalamic relay station nucleus ovoidalis is devoid of immunostained somata. This nucleus contains a high density of punctate immunoreactive structures presumed to be GABAergic axon terminals. In the auditory forebrain center field L and the auditory portions of the hyperstriatum ventrale, up to 8% of the cells were immunopositive. These neurons were significantly smaller than estimated from measurements of the overall cell population in these nuclei. From the two-dimensional arrangement of immunopositive neurons it is suggested that the GABAergic system in the avian auditory telencephalon consists of two separate groups of neurons: one subgroup mediating local inhibitory interactions, the other responsible for lateral inhibition between different frequency representations.
authors.affiliation: Institut für Zoologie, Technische Hochschule Darmstadt, Federal Republic of Germany.
authors.forename: C M
authors.initials: CM
authors.lastname: Müller
mesh_terms: D000818:Animals; D001306:Auditory Pathways / Q000166:cytology*; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008636:Mesencephalon / Q000166:cytology; D009474:Neurons / Q000166:cytology; D005680:gamma-Aminobutyric Acid / Q000032:analysis* / Q000276:immunology
chemical_list: D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase