Animal research demonstrates that nicotine binds to nAChRs in the brain to mediate a variety of behavioral states (Lukas 1998), such as heightened arousal and improved reaction time and psychomotor function (Paterson and Nordberg 2000). Nicotine administration also produces reward through DA release in the NAc, at least in part through stimulation of nAChRs in the VTA (Blaha et al. 1996; Corrigall et al. 1994; Nisell et al. 1994; Yeomans and Baptista 1997; Yoshida et al. 1993). Nicotinic acetylcholine receptors are widespread throughout the brain, with a rank order distribution of nAChR density being thalamus > basal ganglia > cerebral cortex > hippocampus > cerebellum (Broussolle et al. 1989; Cimino et al. 1992; Clarke et al. 1984; Davila-Garcia et al. 1999, 1997; London et al. 1985, 1995; Pabreza et al. 1991; Pauly et al. 1989; Perry and Kellar 1995; Valette et al. 1998; Villemagne et al. 1997).
