Fig. 7.

Enhancing excitatory drive to granule cells increases the activation of GABA_B receptors by endogenous GABA. A, The action of baclofen is partially occluded when dendrodendritic inhibition (DDI) is evoked in Mg²⁺-free aCSF and NBQX (10 μm).Bottom, Summary of results (n = 10).Top, Representative results from one experiment.B, Baclofen has no effect when dendrodendritic inhibition is enhanced in the presence of cyclothiazide (CTZ, 100 μm). The aCSF was supplemented with APV (25 μm) and MK-801 (40 μm) to block NMDARs. Bottom, Summary of results (n = 8). Top, Representative responses from one experiment. The dashed lines represent unity.