Effects of bicuculline on inspiratory activities in piglets.

Antagonism of the alpha receptor sub-type at gamma-aminobutyric acid (GABA) recognition sites in developing pigs was evaluated using the GABAA receptor antagonist bicuculline. The effect of bicuculline infusions was to produce an increase of phrenic and hypoglossal discharge amplitudes. This bicuculline-induced effect on discharge amplitude was manifested in autopower spectra as an increase in the power of peaks located in the medium-frequency (10-50 Hz) band. More importantly, coherence estimates were increased by bicuculline administration demonstrating GABA-mediated influences on a central pattern generator with output in the 10-50 Hz band.