Bicuculline, strychnine and depressant amino acid responses in the anteroventral cochlear nucleus of the cat.

Experiments were conducted in the cat anteroventral cochlear nucleus, comparing the actions of strychnine and bicuculline on amino acid-induced depression of spontaneous and evoked firing. Strychnine reduced responses induced by glycine, taurine and beta-alanine more than GABA or muscimol-induced responses. These latter responses were sensitive to bicuculline. Responses to single and paired tone bursts were not sensitive to strychnine or bicuculline applied either iontophoretically or intravenously. The results indicate that the receptors for depressant amino acids are similar to the receptors found in the cat in other brainstem and spinal cord sites, but differ from those found in the cerebellum, thalamus and cerebral cortex. The data also indicate that these amino acids are not involved either in the response to tone bursts at characteristic frequency or in the suppression of this response by a second, higher frequency tone.