Neurobiological substrates of nicotine addiction
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Almost 10 years ago the United States Surgeon General recognized tobacco smoking as the number one cause of death in the USA that could be prevented, if individuals quit smoking (US Department of Health and Human Services 1988). In the same report, it was also shown that nicotine is the main ingredient in cigarettes that leads to the habit of smoking because the individual gradually become addicted to nicotine and, therefore, tobacco smoking is continued in order to continue the administration of nicotine. In that sense, nicotine is considered to be as addictive as other drugs of abuse such as morphine or heroin, amphetamines and alcohol. The fact that nicotine is addictive is indicated by the fact that smokers frequently fail to quit. As high as 80% of individuals who attempt to quit, resume smoking within one year, even though these individuals are often fully aware of the potential harmful effects of smoking on health. One of the reasons that quitting smoking is difficult is because when a heavy habitual smoker stops smoking, then he/she suffers from several withdrawal symptoms, such as depression anxiety, irritability, restlessness and increased appetite. These symptoms make the person crave and desire tobacco smoking in order to relieve the suffering which results from these symptoms, and `'cure" the nicotine withdrawal symptoms. In the brain, nicotine produces its effects by attaching to and "activating ' specific sites called receptors. The purpose of the present studies is to investigate to which receptors nicotine attaches in order to produce the pleasurable effects that habitual tobacco smokes experience. Other experiments will explore which of these receptors have changed their normal function during repeated tobacco use, so that when nicotine is no longer available in the brain to attach to these receptors, these receptors' actions lead to a series of events that produce the aversive symptoms experienced during nicotine withdrawal. Another series of experiments will investigate whether repeated failed attempts to quit smoking lead to an increased severity in the withdrawal symptoms, thus making it harder for people to quit smoking. The same experiments will also test whether the longer an individual has been a smoker, the harder it is to quit smoking; because for these individuals the pleasurable effects of nicotine are greater compared to the pleasurable effects of nicotine experienced by an individual that just started smoking. Further, other experiments will test whether the more times an individual has tried to quit smoking and failed, the harder it is to quit smoking, because again, for this individual, nicotine has stronger and more powerful pleasurable effects than for non smokers. Finally, other studies will investigate which parts of the brain are involved specifically in the production of nicotine withdrawal symptoms. All of the studies described above will use animal subjects. Such experiments are the types of experiments that will enable us to study exactly which parts of the brain and which receptors are responsible for the development of nicotine addiction, and for the aversive symptoms of nicotine withdrawal. These studies are expected to provide us with valuable information that will help us design effective treatment programs the may involve both behavioral and pharmacological techniques to help people to quit smoking, and thus avoid the detrimental effects of tobacco smoking on health.