Dr. Leslie Morrow's talk caused a stir of excitement. Morrow described discoveries that she and her CAS colleague, Dr. Leslie Devaud, have made concerning a naturally occurring brain neurosteroid. This chemical, allopregnanolone, may protect animals against the development of alcohol dependence by acting on the GABA-A receptor. Morrow and Devaud discovered that allopregnanolone has a calming effect on the brain that is enhanced during alcohol addiction.
Animal studies indicate allopregnanolone can prevent the symptoms of alcohol withdrawal.
In humans it is known that levels of allopregnanolone are higher in women than in men, whereas the incidence of alcoholism is lower in women. This suggests that allopregnanolone may naturally prevent women from developing alcoholism. Dr. Morrow's lab has found that this protective activity is not determined simply by how much of this substance is present in the brain, but how effectively it acts on GABA-A receptors where alcohol also acts. Chronic consumption of alcohol alters the structure and function of GABA-A receptors. This may explain why neurons become less sensitive to alcohol with prolonged exposure and become hyperexcitable during alcohol withdrawal.