Figure 2.

Chronic food restriction-induced augmentation of heroin seeking and extracellular dopamine in the NAc shell. (a) Total number of active and inactive lever responses for FDR (n=10) and sated (n=8) rats (inset), and active lever responses in 10-min time intervals during the 3 h heroin-seeking test in Experiment 1, *p=0.013 compared with sated rats. (b) Extracellular dopamine following re-exposure to the drug environment and during the heroin seeking test in the FDR and sated rats, *p<0.05 compared with baseline levels, #p=0.007 compared to sated rats. (c) Extracellular dopamine following exposure to a novel context in the FDR (n=5) or sated (n=4) rats.