Figure 6.
Intra-VTA infusions of the mGluR1 antagonist JNJ16259685 or protein synthesis inhibitor cycloheximide during the conditioning phase attenuated the acquisition of CPP to cocaine. (a) Timeline of drug treatment and behavioral paradigm. Groups of rats received saline and cocaine place conditioning once daily for 8 days. Vehicle (Veh), JNJ 16259685 (JNJ) or cycloheximide (Cyc) was bilaterally infused into the VTA 30 min prior to each saline- or cocaine-pairing. (b) Pre-test indicates that rats did not exhibit baseline bias in place preference in all groups (n=7–10, p>0.05). (c) Intra-VTA infusions of JNJ16259685 or cycloheximide significantly attenuated CPP in cocaine-conditioned rats but did not affect CPP scores in saline-conditioned rats (n=7–10, *p<0.05, ***p<0.001, Tukey post hoc test). (d) Intra-VTA infusions of JNJ16259685 or cycloheximide did not significantly affect locomotor activity in cocaine- or saline-conditioned rats (p>0.05, n=7–10). Error bars indicate SEM.