Figure 4.

Tonic inhibition in SPNs is gabazine insensitive. A1, Recording from an SPN holding at resting membrane potential where gabazine (GBZ, 25 nm) did not change membrane potential or cell input resistance. A2, In the presence of exogenous GABA, gabazine still failed to alter cell holding potential. B1–3, At the holding potential of 0 mV, no tonic inhibition was detected when different concentrations of gabazine were applied. C, The amplitude of Lf-IPSPs was significantly reduced by 2.5 μm gabazine (p < 0.05).