Brain Mechanism May Explain Cravings that Trigger Alcohol Relapse
Researchers from the Ernest Gallo Clinic and Research Center at the University of California, San Francisco, have discovered a brain mechanism that facilitates alcohol cravings after long periods of abstinence, opening doors for new addiction treatments.
Published in the journal Neuron, the study looked at the impact of alcohol dependency on the nucleus accumbens core, which is known to play a role in motivation and goal-directed behaviors.
Led by Dr. F. Woodward Hopf, the researchers studied rats that had either self-administered alcohol or sugar for two months, followed by three weeks of abstinence. They found that the rats that drank alcohol had increased electrical activity in the nucleus accumbens core after abstaining from alcohol, but the rats that drank sugar did not experience this. The increase occurred because of an inhibition of small-conductance calcium-activated potassium (or SK) channels.
Using medication, the researchers were able to activate the SK channels in the rats that drank alcohol, which significantly reduced alcohol cravings. The same activation in non-drinking rats did not alter the cravings for sugar. This suggests that decreased SK channels and increased activity in the nucleus accumbens core represent a mechanism that causes rats to crave alcohol after abstaining from drinking.
Dr. Antonello Bonci, a senior author of the study, said that the FDA-approved drug chlorzoxazone, a muscle relaxant, has the ability to activate SK channels, which could help alcohol-dependent people experience fewer alcohol cravings and thus be less susceptible to relapse. Human clinical trials would need to be designed to examine whether this drug or other SK activators could reduce problematic drinking in humans.
Source: Science Centric, Brain mechanism may explain alcohol cravings that drive relapse, March 17, 2010