Geneticists Unravel How Genes Impact Addiction
Research at the Clemson University Center for Human Genetics is revealing new insights into how genes impact drug use and addiction through a novel study of susceptibility to the effects of cocaine and methamphetamine in fruit flies.
The research has been published by PLOS Genetics.
The study assesses naturally occurring variation in drug self-administration and change in this behavior on repeated exposure using Drosophila melanogaster, a common fruit fly.
Why fruit flies? As it turns out, 75% of disease-causing genes in humans have a fly counterpart and researchers can precisely control both the genetic background and environment of the flies, including exposure to drugs.
In human populations, susceptibility to the effects of cocaine and methamphetamine varies due to both environmental and genetic factors, making it challenging to render studies on susceptibility to the effects of these drugs.
The study is an important start in understanding the role of genetics in susceptibility to drug use and addiction.
Results show that there is extensive genetic variation in consumption and preference, as well as change in consumption and preference, with repeated exposures for both cocaine and methamphetamine across different genetic backgrounds and that genetic variation for these traits has significant sex- and drug-specific components.
Males and females proved to be quite different genetically in their propensity to consume the drugs.
Further characterization of several of the genes identified in the study appears to implicate neurons that use the neurotransmitter dopamine and structures in the fly brain known as mushroom bodies.
The mushroom bodies are integrative brain centers that are associated with experience-dependent behavioral modifications.
In future studies, the team will examine to what extent variation in mushroom body morphology correlates with drug consumption and preference behaviors.