Figure 4.

GABA_A binding is increased after extinction training. A, B, Binding of H3-Flu in the BLA is significantly increased 2 and 6 hr after extinction in trained animals (2 and 6 hr, n = 4 per group) compared with animals who were fear conditioned but not extinction trained (no extinction group, n = 6). A similar reduction in H3-Flu binding was not observed in the ventral striatum (C). Ba, Bb, Example autoradiographs from no extinction (Ba) and extinction-trained (Bb) animals. Bc, Bd, Pseudocolor images of Ba and Bb, respectively, demonstrating qualitative increases in GABA_A binding within the BLA after extinction. Arrows highlight the location of the BLA complex. ^*p < 0.05. Error bars indicate ±SEM. See Results for statistics.