Effects of PVT silencing on competition between danger and reward. A, Design and procedure for Lever and Lever+ groups. B, Freezing behavior on the conditioning day for tone–shock pairings. C, Defense and reward behavior during tone presentations on the test day. Defense is percentage of observations where freezing was expressed. Reward is sum of approach behavior (lever press and food magazine entry). Data are means ± SEM. *p < 0.05. Group sizes were as follows: eYFP-Lever, n = 8; eYFP-Lever+, n = 7; hM4Di-Lever, n = 7; hM4Di-Lever+, n = 8.