Neurobiological Mechanisms for Alcoholism Essay -- Biology Essays Rese

Neurobiological Mechanisms for Alcoholism While alcohol could well be considered the most socially acceptable psychoactive drug in our society, the dangers of alcohol abuse and addiction are well known. However, not everyone who uses, or even abuses, alcohol will actually become an alcoholic who is physically dependent on the drug. Not all of the mechanisms that cause one to become addicted to alcohol have been clarified. However, there seem to be two main reasons for alcohol addiction. One is that the chronic consumption of alcohol causes changes in the brain that result in a dependence on alcohol. Another is that some individuals have abnormalities in their brains that result in a greater tendency to become addicted to alcohol. The report in 1990 of the discovery of an "alcoholism gene", while not fully supported by subsequent studies, is illustrative of many observations that the brain chemistry of alcoholics is different from nonalcoholics.1 The acute effects of alcohol on the brain result mainly from its effects on the postsynaptic receptor sites for various neurotransmitters.2 The depressant effects of alcohol arise from its action on GABA-A receptors, the principal postsynaptic receptors for the inhibitory neurotransmitter GABA. When stimulated by GABA, these receptors respond by opening an ion channel that allows Cl- ions to enter the neuron, which hyperpolarizes the membrane and reduces the chance for an action potential to occur. These receptors are also sensitive to alcohol, and its presence allows even more Cl- ions to enter the cell, resulting in further inhibition.3 However, the effects of the chronic use of alcohol are quite different, and result in a decreased sensitivity of GABA-A receptors to both alco... ...s/Blum-full.html 2. OTA Report: Biological Basis for Substance Abuse and Addiction http://www.drugtext.nk/norml/aaota_cont.html 3. Center Line Vol 8 No 3 http://www.med.unc.edu/wrkunits/3ctrpgm/alcohol/cenline/8_3_1.html" 4. Ibid. 5. OTA Report 6. SPRINGER LINK - Psychopharmacology - Abstract Volume 129 Issue 2 (1997) pp 99-111 http://link.springer-ny.com/link/service/jounals/00213/bibs/7129002/71290099.htm 7. OTA Report 8. Ibid. 9. American Scientist 10. OTA Report 11. American Scientist 12. Ibid. 13. OTA Report 14. Honours Thesis by Karen Johnson, UNSW Australia 1996 http://javelin.commed.unsw.edu.au/karen/thesis/ 15. American Scientist 16. OTA Report 17. Ibid. 18. American Scientist 19. Honours Thesis (visit this site for a comprehensive listing of major studies on this subject) 20. American Scientist