THE PSYCHOPHARMACOLOGICAL BASIS OF NICOTINES DIFFERENTIAL-EFFECTS ON BEHAVIOR - INDIVIDUAL SUBJECT VARIABILITY IN THE RAT

Nicotine, the presumed active pharmacological agent in tobacco, produc es variable effects on behavior that are at best described as ''parado xical'' in nature. Thus, nicotine, via tobacco use in humans or nicoti ne administration in experimental animals, tends to transpose behavior depending on predrug baseline rates of behavior. High rates of behavi or appear to be reduced, while low rates of behavior appear to be incr eased by nicotine. This work further proposes that nicotine's variable effects on behavior may be related to its capacity to act as a behavi oral agonist and/or antagonist via its ability either to activate or t o desensitize distinct central nicotinic acetylcholinergic receptors ( nAChR's). Nicotine is portrayed as a neuronal modulating agent that ca n affect behavior contingent upon the genetic makeup of the individual subject being studied. Depending on the structure, function, and loca tion of distinct nAChR's, nicotine appears to be able to induce a wide range of behavioral effects important to the tobacco user. However, t his does not rule out the role the importance that other biogenic amin e systems (i.e., serotonin or dopamine) may have in the genetics of to bacco use or nicotine's variable effects on behavior.