Fig. 5.

Comparison of post-drug infusion responses in simultaneously recorded mPFC and NAc neurons. A, Raster and perievent histogram plots for a mPFC neuron during the heroin self-administration trials of a heroin–cocaine self-administration session. An increase in firing rate was observed after heroin self-administration that occurred at 0 sec. B, Same neuron depicted in A during the cocaine self-administration period of the same session. No significant change in firing rate was found during cocaine self-administration.C, This NAc neuron did not change its firing rate after the lever press during the heroin self-administration trials.D, Same NAc neuron as in Cdisplayed an inhibitory response after cocaine self-administration during the same session. This neuron also exhibited an excitatory anticipatory response immediately before the lever press at 0 sec.