Nicotine, the primary component of tobacco produces reinforcing effects both in humans and animals. The neurochemical, anatomical and molecular basis of nicotine dependence is very similar to the other drugs of abuse, particularly the psychostimulants…

Nicotine, is derived from the leaves of tobacco be- longing to the family Nicotiana tabacum and has been in use for centuries. It can be smoked, chewed, or sniffed. Nicotine was isolated from tobacco leaves in 1828 by Posselt and Reimanbasic, since then scientists began studying its effects in the brain and body. This research eventually showed that, although tobacco contains thousands of chemicals, the most active ingredient that acts in the brain and produces addiction is nicotine. Nicotine is an alkaloid (1-me-thyl-2-[3-pyridyl] pyrrolidine). It is the primary com-ponent of tobacco that leads to addiction. More re-cent research has shown that the addiction produced by nicotine is extremely powerful and is atleast as strong as addictions to other drugs such as heroin and cocaine. In recent years, the use of tobacco has taken a great toll on youth and society. In fact, to-bacco is the gateway drug to other drugs of abuse such as marijuana and alcohol. The notable aspect about tobacco use is that it consistently occurs early in the sequence of problem behaviors. When a young person starts smoking or using tobacco, it is a sig-nal, an alarm that he or she may get involved in other risky behaviors. How nicotine acts?. Nicotine acts on the brain and other parts of the ner- vous system. When tobacco is smoked, nicotine enters the bloodstream through the lungs and reaches the brain faster than the drugs that enter the body directly through the veins. When it is chewed or sniffed, nicotine passes through the mu-cosal membranes of the mouth and nose to enter the bloodstream. Nicotine can also enter the blood-stream by passing through the skin. Nicotine reaches the brain within seven seconds. Nicotine and the brain. Recent research has shown how nicotine acts on the brain to produce a number of behavioral effects. Nicotine readily crosses the blood brain barrier stimulating the nicotinic acetylcholine receptors (nAChR). These nicotinic cholinergic receptors are one of the major acetylcholine receptor subtypes. The stimulation of the presynaptic nAChRs on these neurons increases the transmitter release as well as the metabolism. Biological theories of nicotine addiction. I. Dopamine and reward pathways There is substantial evidence to suggest that nico-tine plays a vital role in maintaining the tobacco smoking habit and many habitual smokers become dependent on nicotine. Nicotine is a powerful rein-forcing agent in both animals and humans. The means by which nicotine produces addiction remain unclear. Behavior studies in animals do indicate that nicotine is…

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