Scientists at the National University of Singapore (NUS) School of Medicine have identified a key genetic regulator of the inherent sensitivity to alcohol and the risk of alcohol dependence.
The study, published in the Journal of Neuroscience, provides experimental evidence for the first time directly linking the CHRNA3 gene to alcohol consumption.
The research significantly expands our knowledge of how genetic predisposition affects the development of addiction.
The study was conducted on preclinical laboratory animal models. Scientists used specific conditions where the animals could voluntarily consume alcohol.
Under normal conditions, the animals initially showed an attraction to alcohol, but as the amount of alcohol increased, they quickly switched to alcohol avoidance behavior.
However, animals with the CHRNA3 gene mutation exhibited reduced sensitivity to alcohol.
Animals with this mutation transitioned to avoidance behavior much later, consumed alcohol for a considerably longer period, and tolerated higher concentrations of it.
The scientists discovered that the mutation affects the chemical signals in the brain that control brain activity (excitation and sedation). Consequently, this mutation weakens the usual sedative effect of alcohol. Since the body feels the effect of alcohol less, this increases the probability of excessive alcohol consumption.
The researchers believe that knowing such genetic risk factors will help us create individualized and effective strategies for those with a genetic predisposition to addiction.
