Figure 1.
Inhibition of de novo protein synthesis impairs conditioned freezing after extinction trials without affecting retrieval. A, Dose-dependent impairment consolidation of contextual fear by anisomycin. There were nine mice per group. B, Anisomycin (50 μg, i.h.) injected after the first nonreinforced trial (US-) also decreased context-dependent freezing without affecting tone-dependent freezing (C) when compared with the vehicle group. D, Anisomycin injected after a reinforced trial did not affect freezing. E, Anisomycin injected without memory reactivation did not affect freezing. F, Anisomycin did not affect freezing when it was injected intrahippocampally 1 hr before the first or second (G) memory test. Statistically significant differences: *p < 0.01, **p < 0.001 versus vehicle control; ap < 0.01 versus test 1. Arrow indicates the anisomycin or vehicle injection. T, Training.