Figure 8.

Average CS+ responses before and after the drug-free period. A, B, Population perievent histograms showing the average responses of neurons exhibiting either an excitatory (A) or inhibitory (B) response to the CS+. In each histogram, the average normalized firing rate is plotted as a function of 0.25 s time bins for the 10 s pre-CS+ and the 10 s CS+ period. The vertical dashed line at time 0 represents the onset of the CS+. C, D, For neurons exhibiting CS+ responses, the average normalized firing rate during the CS+ and CS− periods is plotted for the 0 and 0.25 mg/kg AMPH sessions both before and after the drug-free period. C, Neurons excited during the CS+. D, Neurons inhibited during the CS+. Error bars represent SEM. **p < 0.01.