Abstract
γ-Aminobutyric acid (GABA) immunoreactivities were found by immunohistochemistry in the chemoreceptor cells of the cat carotid body at the light microscopic level. The immunohistochemical process used consisted of a strept-avidin-biotin-peroxidase method. The immunostaining was mostly weak and appeared in about one-third of the cells. The scarcity of GABA immunoreactivities provides an explanation for the previously reported meager interactive effects on respiration of the elaboration of the GABA-ergic and chemoreceptor systems found in the cat at the functional level. Therefore, GABA would be an unlikely essential modulator of the chemosensory function in the cat.
