The Science of Addiction

It is no secret that addiction, whether to a drug, alcohol, tobacco or certain behavior, can have detrimental effects on one’s quality of life. According to one National Survey on Drug Use and Health, 23.5 million individuals aged 12 or older needed treatment for some substance-related addiction.  It is also important to note that the number of individuals that are actually affected by addiction is likely to be much higher as the number of individuals who go without seeking attention for their addiction is greater than those who do. Thus, it is important for us to gain a deeper level of understanding of how these neural pathways work in order to develop means of counteracting this behavior of dependency.

         

             Addiction to nicotine is a prevalent form of addiction in the United States. It is estimated that approximately 29% of the population abuse cigarettes, on average. In a recent research study conducted by Danyan Mao, Keith Gallagher, and Daniel S. McGehee, the question of how nicotine dependence is described in terms of the receptor systems is discussed. The results concluded that nicotine activates nicotinic receptors (nAChRs) to initiate a series of adaptive changes in the ventral tegmental area (VTA) of the brain. The increase in activation of these nicotinic receptors leads to greater presynaptic glutamate release, which therefore induces long-term potentiation and synaptic plasticity. Lastly, the research found striking similarities in the biological mechanism “underlying synaptic plasticity induced by nicotine and cocaine in the VTA.”

             The particular type of VTA neurons for which nicotine induced long term potentiation and synaptic plasticity occurs are the dopamine neurons. In one New York Times article, it is reported that the human brain is attracted to things that were once pleasing, even if they no longer are. In the study, recollection of the previously pleasing stimulus still showed dopamine release in the brain, indicative of addictive behaviors, even when there was no reward present. This study regarding dopamine release, in conjunction with the study regarding the nicotinic pathway in the VTA can lead to greater insight to understanding and treating addiction concerns in the future.

References:

National Institute on Drug Abuse. Treatment Statistics Retrieved from https://www.drugabuse.gov/publications/drugfacts/treatment-statistics on March 4, 2016

Mao, Danyan, Keith Gallagher, and Daniel S. McGehee. “Nicotine Potentiation of Excitatory Inputs to VTA Dopamine Neurons.” The Journal of neuroscience : the official journal of the Society for Neuroscience 31.18 (2011): 6710–6720.PMC. Web. 4 Mar. 2016.

Bhanoo, Sindya N. "Our Brains Remember the Good Stuff." The New York Times. The New York Times, 15 Feb. 2016. Web. 04 Mar. 2016.

URL: http://www.nytimes.com/2016/02/16/science/our-brains-remember-the-good-stuff.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science&region=stream&module=stream_unit&version=search&contentPlacement=6&pgtype=sectionfront&_r=0