Table of Contents
ISRN Neurology
Volume 2012 (2012), Article ID 972607, 24 pages
http://dx.doi.org/10.5402/2012/972607
Review Article

Current Perspectives on the Neurobiology of Drug Addiction: A Focus on Genetics and Factors Regulating Gene Expression

1The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3010, Australia
2Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC 3010, Australia

Received 16 August 2012; Accepted 6 September 2012

Academic Editors: C.-Y. Hsu and A. Mamelak

Copyright © 2012 Jhodie R. Duncan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Drug addiction is a chronic, relapsing disorder defined by cyclic patterns of compulsive drug seeking and taking interspersed with episodes of abstinence. While genetic variability may increase the risk of addictive behaviours in an individual, exposure to a drug results in neuroadaptations in interconnected brain circuits which, in susceptible individuals, are believed to underlie the transition to, and maintenance of, an addicted state. These adaptations can occur at the cellular, molecular, or (epi)genetic level and are associated with synaptic plasticity and altered gene expression, the latter being mediated via both factors affecting translation (epigenetics) and transcription (non coding microRNAs) of the DNA or RNA itself. New advances using techniques such as optogenetics have the potential to increase our understanding of the microcircuitry mediating addictive behaviours. However, the processes leading to addiction are complex and multifactorial and thus we face a major contemporary challenge to elucidate the factors implicated in the development and maintenance of an addicted state.