Figure 5. HIV-1 Tat potentiates morphine-conditioned place preference 24 h post morphine and maraviroc pretreatment exacerbates this effect.

Tat(−) or Tat(+) mice (n = 11 - 14 / group) were assessed for their chamber preference (open circles) in a biased conditioned place preference (CPP) test consisting of either (A) two cycles of saline (i.p.)/morphine (10 mg/kg, i.p.) conditioning (closed squares), (B) four cycles of saline/morphine conditioning (closed squares), or (C) four cycles of vehicle (p.o.) or maraviroc pretreatment (gray triangles) followed by saline/morphine conditioning (closed squares). Initial preferences for the morphine-paired chamber (left of dashed line) are depicted followed by final CPP (right of dashed line) after (A′) two conditioning cycles, (B′) four conditioning cycles, or (C&prime) vehicle/maraviroc pretreatment prior to four conditioning cycles. Tat(−) mice are depicted in open bars, Tat(+) mice are depicted in hatched bars, vehicle (p.o.)-pretreated mice are depicted with white bars, and maraviroc (62 mg/kg, p.o.)-pretreated mice are depicted with black bars. † main effect for the final chamber preference to differ from the initial preference. * interaction for Tat(+) mice to differ from Tat(−) mice. ‡ interaction for maraviroc-pretreated Tat(+) mice to differ from all other groups, p < 0.05.