Nicotine binds selectively to acetylcholine receptors at the autonomic ganglia, in the adrenal medulla, at neuromuscular junctions, and in the brain. Two types of central nervous system (CNS) effects are believed to be the basis of nicotine’s positively reinforcing properties. A stimulating effect, exerted mainly in the cortex via the locus ceruleus, produces increased alertness and cognitive performance. A ‘reward’ effect via the ‘pleasure system’ in the brain is exerted in the limbic system.