On Booze

by F.

Recreational drugs seem to be the theme today. First THC, now alcohol. Nature Reviews Neuroscience 7, 593 (August 2006) summarizes some research published by Daws, L. C. et al. under the title Ethanol inhibits clearance of brain serotonin by a serotonin transporter-independent mechanism. J. Neurosci. 26, 6431–6438 (2006):

A new study shows that ethanol inhibits clearance of the neurotransmitter serotonin (5-HT) from the extracellular fluid in the mouse hippocampus, and that, surprisingly, this occurs through a mechanism that is independent of the serotonin transporter (5-HTT).

5-HTT is the serotonin transporter inhibited by SSRIs like fluoxetine (Prozac). Here’s the money quote:

This work clearly establishes that blocking the removal of 5-HT underlies, at least in part, the effects of ethanol in the brain. It remains to be determined exactly how ethanol inhibits 5-HT removal from the extracellular fluid. The noradrenaline transporter, which also transports serotonin and is expressed in the hippocampus, is one candidate site of action. However, more work will be required to confirm a role for this transporter in the influence of alcohol on neuronal function and behaviour. These findings could help to explain the positive association between a polymorphism in the promoter region of human 5-HTT, which confers low-expression of 5-HTT, and alcoholism.

Review article is here. Original article here.