Figure 6. Influence of the GABAA receptor antagonist PTX and the GABAB receptor antagonist CGP54626 on the effect of exogenous application of GABA as well as the influence of the GABAB receptor antagonist CGP54626 on 470 nm light-induced inhibition of the frequency of sEPSCs in VTA-DA neurons.
(A) Influence of the GABAA receptor antagonist PTX on the effect of exogenous application of GABA of VTA-DA neurons in rats. Left panel: typical current traces of sEPSC before and after GABA (10 μM) in the presence of PTX (100 μM). Middle panel: typical time course of the frequency of sEPSCs before and after GABA (10 μM) in the presence of PTX (100 μM). Right panel: average frequency of sEPSCs before and after GABA (10 μM) in the presence of PTX (100 μM) (n = 6 cells from four rats, p < 0.05, compared to PTX before GABA). (B) Influence of the GABAB receptor antagonist CGP54626 on the effect of exogenous application of GABA of VTA-DA neurons in rats. Left panel: typical current traces of sEPSC before and after GABA (10 μM) in the presence of CGP54626 (2 μM). Middle panel: typical time course of the frequency of sEPSCs before and after GABA (10 μM) in the presence of CGP54626 (2 μM). Right panel: average frequency of sEPSCs before and after GABA (10 μM) in the presence of CGP54626 (2 μM) (n = 6 cells from four rats, p = 0.87). (C) Influence of the GABAB receptor antagonist CGP54626 on 470 nm light-induced inhibition of the frequency of sEPSCs of VTA-DA neurons in mice. Left panel: typical current traces of sEPSCs before and after blue light (470 nm) stimulation in the presence of CGP54626 (2 μM). Middle panel: typical time course of the frequency of sEPSCs before and after blue light (470 nm) stimulation in the presence of CGP54626 (2 μM). Right panel: average frequency of sEPSCs before and after blue light (470 nm) stimulation in the presence of CGP54626 (2 μM) (n = 6 cells from five mice, p = 0.21). Data are shown as the mean ±s.e.m. *p < 0.05.