Contributions of dopamine terminal areas to amphetamine-induced anorexia and adipsia

Systemic injections of amphetamine produce both anorexia and adipsia. Evidence suggests that it is the stimulation of activity by the drug in both noradrenergic and dopaminergic synapses that mediate these effects. The present study examined the contributions of dopamine terminal regions to these effects in rats by microinjecting amphetamine directly into one of six discrete sites (medial frontal cortex, nucleus accumbens, anteromedial caudate nucleus, ventrolateral caudate nucleus, amygdala, or the region surrounding the area postrema) and observing the effects of the injections on eating or drinking. The rats were mildly deprived of either food or water and following microinjection of either amphetamine or saline, were given access to food or water. Injections of amphetamine into either the nucleus accumbens or amygdala caused both anorexia and adipsia but no effects were observed from the other sites. It is suggested that the amphetamine's action on these two sites contributes to the anorexia and adipsia that are observed after systemic injection of the drug. Possible behavioral mechanisms for the effects are discussed.