CEm synaptic plasticity involved in fear regulation is impaired in BDNFMet/Met mice. (a) Percentage freezing on test day (day 3) in BDNFVal/Val mice (TA=6 mice, FC=10 mice, and FE=7 mice). (b) Percentage freezing on test day (day 3) in BDNFMet/Met mice (TA=6 mice, FC=11 mice, and FE=9 mice). (c) EPSC amplitude in the CEm neurons of TA (15 neurons/6 mice), FC (13 neurons/7 mice), and FE (14 neurons/7 mice) groups of BDNFVal/Val mice. (d) EPSC amplitude in the CEm neurons of TA (13 neurons/6 mice), FC (17 neurons/8 mice), and FE (19 neurons/9 mice) groups of BDNFMet/Met mice. Asterisk denotes a statistically significant difference.