Figure 3. Involvement of GABA_A receptor-mediated inhibition in rhythmic activity within rat substantia gelatinosa in vitro.

A, potassium-induced rhythmic activity before (left panel) and after 30 min 30 μm bicuculline (middle panel). B, bicuculline reduced the power amplitude and area of the spectrum (middle panel) and on drug washout there was a partial reversal of this effect (right panel). C, bicuculline had no effect on the frequency of the oscillation. D, quantified data (n = 6) reveal that bicuculline reduces the peak power amplitude and the power area with no significant effect on the frequency of activity. *P < 0.05 paired t test versus control.