Repeated access to sucrose augments dopamine turnover in the nucleus accumbens.

Dopamine in the nucleus accumbens has been implicated in motivated behavior, including feeding. Normal feeding occurs in patterns, but little is known about how these schedules influence this neural system. We hypothesized that repeated access to preferred foods would augment dopamine clearance. Rats on a restricted feeding schedule had access to 0.3 M sucrose or water followed 2 h later by chow. The rats were kept on this regimen for 7 days, with microdialysis performed on the last day. During the chow period, dopamine turnover in the nucleus accumbens was higher when preceded by sucrose than by water. This finding suggests that, under some dietary conditions, neuroadaptation occurs in response to feeding and these changes may, in turn, influence future meals.