FIGURE 3.
GABAB receptor activation in the hippocampus of wild-type and BAC transgenic mice. A, peak amplitudes of EPSCs recorded in CA1 neurons at −80 mV were similarly (p > 0.05) reduced in the presence of baclofen (50 μm) in wild-type (n = 8), NTAP-GABAB1a (n = 5), and GABAB1a/b-CTAP (n = 5) transgenic mice, as summarized in the bars and illustrated by representative current traces. Scale bars, 100 pA, 20 ms. B, peak amplitudes of IPSCs recorded at 0 mV were similarly (p > 0.05) reduced by baclofen (50 μm) in wild-type (n = 6), NTAP-GABAB1a (n = 6), and GABAB1a/b-CTAP (n = 4) transgenic mice. Scale bars for representative current traces, 50 pA, 20 ms. CGP54626 (5 μm) reversed the baclofen-mediated effects on EPSCs and IPSCs. All of the current traces are the averages of six consecutive traces. C, summary of changes in holding current recorded in the presence of tetrodotoxin (1 μm) at −50 mV following baclofen perfusion, reflecting activation of G-protein-regulated inwardly rectifying potassium channel currents in wild-type (n = 7), NTAP-GABAB1a (n = 3), and GABAB1a/b-CTAP (n = 4) transgenic mice. wt, wild-type.