Nicotine increases microdialysate brain amino acid concentrations and induces conditioned place preference

The action of nicotine on the nicotinic receptor-mediated release of inhibitory and excitatory acids in the nucleus accumbens, NAC, of freely moving rats was studied in order to clarify their effects' on reinforcing behavior as estimated by conditioned place preference (CPP). Using the technique of microdialysis, intraperitoneal (i.p.) injections of nicotine (0.15-0.3-0.6 mg/kg), significantly increased aspartate, glutamate, arginine, taurine, and alanine microdialysate content in the nucleus accumbens. The same doses of nicotine were able to elicit a reinforcing effect in a CPP paradigm which was probably associated with the increased brain levels of excitatory acids triggering additional dopamine release in the mesolimbic system.