D1 Receptors in Maoi and Nicotine Self-administration

Tobacco smoking is the leading cause of preventable death in the United States, taking the lives of about 440,000 people (Centers for Disease Control, 2004). It is commonly believed that nicotine is the key agent in the addictive properties of tobacco smoking. Nicotine is a direct agonist of nicotinic acetylcholine receptors, which are largely expressed through the brain. At the present time, nicotine replacement therapy (NRT) is used as a substitute treatment to help smokers to stop tobacco consumption (Silagy et al., 1994). However, NRT seems to only improve tobacco withdrawal partially. Moreover other studies have shown that denicotinized cigarettes were also efficient to decrease withdrawal and craving signs (Pickworth et al., 1999). Finally, tobacco smoke contains about 3000 different compounds and it is possible that some of them are involved, as nicotine, in the addictive processes induced by tobacco (Pickworth et al., 1999).