Figure 6: Pre-extinction Nimodipine has no effect on memory extinction.

(a) Experimental timeline. Following contextual fear conditioning (C), Nimodipine was injected 1 h before extinction (E). (b) Subsequent freezing behaviour was compared across the post-reactivation/extinction test (T1/Test 1) and the post-reacquisition test (T2/Test 2). Both vehicle- (open columns/symbols) and Nimodipine-treated (filled columns/symbols) rats readily reconditioned. (c) Freezing during the extinction session itself did not differ between groups. Contextual freezing was compared across seven 4-min bins corresponding to the final 28 min of extinction after reactivation or the first 2 min of extinction. There were no differences between the groups during extinction (bin×treatment: F(2.2,22.1)=2.038, P=0.150; treatment: F(1,10)=0.020, P=0.889). However, there was also no evidence for a reduction of freezing over the course of the session (bin: F(2.2,22.1)=1.762, P=0.193). Data presented as mean+s.e.m. N=6 per group.