Fig. 5.
Cue-by-cue pattern of lever pressing during the PIT test. The time course of pressing is shown during an entire 30-min extinction test session. The symbols show baseline lever pressing [pre-conditioned stimulus (CS) and post-CS 30-s bins], intense cue-triggered surges of lever pressing induced during the CS+ (sucrose cue; red) and in the immediately following 30-s bin (red), and the relative lack of effect of CS−. Amphetamine (top) or DAMGO (middle row) microinjections in the core (left) or medial shell (right) all dramatically amplified cue-triggered surges far above control vehicle levels (bottom).