DISCRIMINATIVE STIMULUS PROPERTIES OF NICOTINE - APPROACHES TO EVALUATING POTENTIAL NICOTINIC RECEPTOR AGONISTS AND ANTAGONISTS

The prototypic nicotinic acetylcholinergic receptor (nAChR) agonist, n icotine, is one of the primary psychoactive ingredients of tobacco. Th is review examines the effects of nicotine and similar compounds in ni cotine discrimination procedures, a paradigm in which the subjective e ffects of nicotine can be modeled in animals. Results of these studies have shown that the discriminative stimulus effects of nicotine are s hared by nicotine analogues and by the novel nicotinic agonists, epiba tidine and ABT-418, and can be antagonized by the nAChR channel blocke r, mecamylamine. Individual and strain differences in sensitivity to t he discriminative stimulus effects of nicotine have been noted, sugges ting the possibility of genetic differences in the functioning of nACh receptors or related processes. In human smokers, individual variabil ity is also observed; however, the degree of within smoker (but betwee n situation) variability far exceeds between smoker variability. Furth er research into the ways in which situational factors affect the disc riminative stimulus effects of nicotine is needed. (C) 1996 Wiley-Liss , Inc.