Several lines of evidence suggest that stimulation of both nicotinic and muscarinic cholinergic receptors can affect mesolimbic DA levels and modify the reinforcing value of self-administered drugs. In this regard, the action of nicotine (the prototypical agonist at nicotinic ACh receptors) on the mesolimbic DA system has been studied extensively (for review see [27]) as has its interaction with other drugs of abuse such as alcohol [28,29] and cocaine [30,31]. These studies demonstrate that nicotinic activation increases extracellular DA in the NAc, stimulates locomotor activity with repeated exposure, and potentiates the reinforcing value of cocaine.
