Fig. 7. Comparative efficacy of allopregnanolone on GABA-gated currents in wildtype (A) and δ-subunit knockout (B) mouse dentate gyrus granule cells.
Concentration-dependent responses of allopregnanolone (AP) potentiation of inward chloride current in the presence of 3 μM GABA in DGGCs. Recordings were at -70 mV voltage-clamp, whole-cell patch of in acutely dissociated DGGCs. GABA was first locally applied to the bath solution for 5 seconds to establish a baseline level of gated, inward chloride current. Increasing concentrations of AP were applied for 10 seconds. After 5 seconds of application, GABA perfusion was initiated, resulting in concentration-dependent potentiation by AP. AP alone did not elicit a change in current, however, at 500 nM and 1 μM concentrations, AP application produced a slight inward current.