Fig. 2.

BN1 substitution rescues long-term auditory and contextual fear memory deficits in the FHH strain. a Procedure for the 2 days of testing. 24 h after training, animals were placed into Context B and given a 5 min, nonreinforced CS presentation after a 6 min baseline period and were placed into Context A for a 15 min test of the contextual CS. There was 4 h between each test and the order was counterbalanced for all strains. b The FHH strain had a long-term memory deficit for the auditory CS, relative to the BN strain. Introgression of the BN1 chromosome rescues this impairment. c The FHH strain showed marginal impairments in long-term memory for the contextual CS relative to the BN strain. Substitution of the BN1 chromosome onto the FHH background significantly enhances LTM for the contextual CS. * denotes P < 0.05