Cigarette;  Smoking;  Tobacco

Nicotine is a psychostimulant alkaloid that is addictive and heavily used in cigarettes and other tobacco-related products. It is primary metabolized by the liver to cotinine, and the average half-life is 2 h.

Upon administration, nicotine binds to nicotinic cholinergic receptors (nAChRs), ligand-gated ion channels composed of several subunits, that are located in central and peripheral nervous systems. Stimulation of nAChRs by nicotine leads to the release of various neurotransmitters. Of those, dopamine secreted in the mesolimbic area and the frontal cortex mediates pleasurable experience and rewarding pathways linked to the positive reinforcement of nicotine (Benowitz, 2010). Other neurotransmitters, such as norepinephrine, acetylcholine, glutamate, serotonin, beta-endorphin, and gamma-aminobutyric acid (GABA), are also released in response to nicotine and mediate its effects on attention, tension reduction, and...