Figure 1.

Impairments relating to various components of reward processing are evident after withdrawal from chronic amphetamine administration. (A) Rats displayed an elevation of ICSS thresholds, reflecting a reward deficit, after withdrawal from chronic amphetamine administration (closed circles), compared to saline-treated controls (open circles). B: Baseline [Modified with permission from Paterson et al., 2000]. (B) Withdrawal from chronic amphetamine treatment significantly reduced the breakpoint for a sucrose pellet in a progressive-ratio schedule task, reflecting a motivational deficit, an effect that persisted for up to 29 days. B: Baseline [Modified with permission from Der-Avakian and Markou, 2010]. (C) Rats trained to anticipate the introduction of a sexually receptive female displayed fewer anticipatory side changes during amphetamine withdrawal, compared to saline-treated controls, reflecting an anticipatory deficit [Taken with permission from Barr and Markou, 2005, and originally from Barr et al., 1999]. (D) Amphetamine withdrawal was also associated with an increased post-ejaculatory interval, reflecting a reduction in an additional component of motivated sexual behavior [Taken with permission from Barr and Markou, 2005, and originally from Barr et al., 1999]. (E) Withdrawal from an escalating amphetamine treatment schedule produced alterations in a successive negative contrast procedure in rats, reflecting an increased negative reaction to reward devaluation. Amphetamine withdrawal significantly reduced consumption of a sucrose solution when the concentration was unexpectedly downshifted (from 32% to 4%) compared to saline-treated rats, and significantly increased the time to return to the consumption levels of control rats [Taken with permission from Barr and Markou, 2005, and originally from Barr and Phillips, 2002].