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 GAB A(A) receptor antagonist bicuculline. The effect of bicuculline infusi ons was to produce an increase of phrenic and hypoglossal discharge am plitudes. This bicuculline-induced effect on discharge amplitude was m anifested in autopower spectra as an increase in the power of peaks lo cated in the medium-frequency (10-50 Hz) band. More importantly, coher ence estimates were increased by bicuculline administration demonstrat ing GABA-mediated influences on a central pattern generator with outpu t in the 10-50 Hz band.