Timing of behavioral responding to long-duration Pavlovian fear conditioned cues.

Behavioral responding is most beneficial when it reflects event timing. Compared to reward, there are fewer studies on timing of defensive responding. We gave female and male rats Pavlovian fear conditioning over a baseline of reward seeking. Two 100-s cues predicted foot shock at different time points. Rats acquired timing of behavioral responding to both cues. Suppression of reward seeking was minimal at cue onset and maximal before shock delivery. Rats also came to minimize suppres-sion of reward seeking following cue offset. The results reveal timing as a mechanism to focus defen-sive responding to shock-imminent, cue periods.