Figure 3. Biphasic modulation of [³⁵S]TBPS binding to recombinant α1β2γ2 receptors by GABA.

Specific, picrotoxin (100 μm)-displaceable [³⁵S]TBPS binding to α1β2γ2 receptors in HEK293 membrane homogenates was normalized to baseline binding in the absence of GABA (% control binding). Low concentrations of GABA (0.03–1 μm) enhanced baseline binding, while high concentrations of GABA (>1 μm) inhibited binding below baseline. Data are representative of the means ± SEM of 5–8 independent experiments performed in triplicate.