Grm7−/− mice have deficits in associative fear learning despite intact long-term potentiation at SC-CA1 synapses. A, Quantification of acute freezing during baseline (BL) and in response to foot shocks (S1 and S2) during fear conditioning. B, Quantification of freezing behavior upon re-exposure to the conditioning context 24 hours postconditioning. For (A) and (B), N = 20 Grm7+/+ (11 female, 9 male), 30 Grm7+/− (16 female, 14 male), 26 Grm7−/− (15 female, 11 male). C, Quantification of freezing behavior in response to a 1-minute auditory cue 4 hours after the context test. N = 15 Grm7+/+ (9 female, 6 male), 25 Grm7+/− (13 female, 12 male), 22 Grm7−/− (12 female, 10 male). Five Grm7+/+, five Grm7+/− and four Grm7−/− animals were excluded because of freezing >20% prior to the tone. D, Long-term potentiation at SC-CA1 synapses induced by two trains of high frequency stimulation (HFS, 100 Hz). N (total slices/total mice) = 15/9 Grm7+/+ (10/6 female, 5/3 male), 13/8 Grm7+/− (6/4 female, 7/4 male), 15/8 Grm7−/− (8/4 female, 7/4 male). E, Quantification of LTP magnitude during the last 5 minutes of recording (gray bar in D). *P < .05, ***P < .001, ****P < .0001