A research group under the leadership of Linköping University Professor Markus Heilig has identified an enzyme whose production is turned off in nerve cells of the frontal lobe when alcohol dependence develops. The deficiency in this enzyme leads to continued use of alcohol despite adverse consequences.
The enzyme, PRDM2, has previously been studied in cancer research, but we didn't know that it has a function in the brain," says Markus Heilig, professor of psychiatry and head of the Center for Social and Affective Neuroscience (CSAN) at Linköping University.
He and his research group are linking together research into alcoholism and other addictive illnesses with advanced brain research. It has long been suspected that people with alcohol dependence have impaired function in the frontal lobes of the brain, but the underlying biological mechanisms have not been known. The research team behind the paper, which includes researchers from both Linköping University and University of Miami, is the first to identify this molecular mechanism.
If frontal function is impaired, it is difficult for us to control our impulses. A person with intact impulse control can walk past a bar on a warm day and think 'A beer would be nice, but I can't have one now because I have to get back to work'. An alcoholic does not have sufficient impulse control to refrain, thinking: 'It's hot and I'm thirsty'.
"PRDM2 controls the expression of several genes that are necessary for effective signalling between nerve cells. When too little enzyme is produced, no effective signals are sent from the cells that are supposed to stop the impulse," Professor Heilig tells us.