Figure 9.

The effects of morphine withdrawal on appetitive motivations for social or sexual reward in male rats under a restricted-approach condition (i.e., during the effort-based or risky appetitive behavior testing). The testing was performed on day 7 of withdrawal. (A) The maximum height of the partition that animals were willing to climb over to approach the stimulus-cage holding a male or estrous female rat. (B) The total score for the amounts of difficulty that animals were willing to conquer (i.e., climb over a continuously heightened board thick with pins) to approach the stimulus-cage holding a male or estrous female rat. ^*P < 0.05, ^***P < 0.001, relative to saline group. Values are mean ± s.e.m.