The effects of water-odor preference conditioning in the preadolescent nucleus accumbens septi

The mesolimbic dopamine (DA) pathway is critical in reward-mediated behavior. Water, sucrose, and drugs of abuse all increase DA in the nucleus accumbens septi (NAcc) in adult animals. Recently our laboratory has shown that cocaine and alcohol increase DA efflux in preadolescent animals. The present study used a natural reinforcer (i.e., water) at postnatal day 25 (PND 25) to determine the sensitivity and responsiveness of this pathway. Repeated pairing of a peppermint odor with water resulted in a behavioral odor preference and an odor-elicited increase in accumbal DA. Results show that this developing pathway is functional and responsive to conditioning using a natural reinforcer and that these behavioral and neurochemical responses can be conditioned to a previously novel environmental stimulus.