Will rapamycin help with alcoholism as well?

Rats were cured of alcoholism with the help of an immunosuppressant

Copper news based on Nature News: Blocking boozy memories reduces risk of relapseNeuroscientists from the University of California (San Francisco), experimenting on rats suffering from chronic alcoholism, were able to use the drug rapamycin to rid them of alcohol-associated memories, thus preventing a relapse.

The authors of the study suggest that rapamycin may become a promising tool for the treatment of alcohol dependence. The work was published in the journal Nature Neuroscience (Barak et al., Disruption of alcohol-related memories by mTORC1 inhibition prevents relapse).

Rapamycin (Sirolimus) is a product of the vital activity of bacteria of the species Streptomyces hygroscopicus, first isolated from a soil sample from Easter Island (Rapa Nui). This drug is used in transplantology as an immunosuppressant to combat rejection of transplanted organs and tissues. The mechanism of action of this substance differs from other immunosuppressants – it is an inhibitor of the intracellular multimolecular signaling complex mTORC1, which ultimately leads to suppression of lymphocyte activation and decreased immunity. It has also been reported that rapamycin, by suppressing the activity of the regulatory protein mTOR, slows down aging in flies, roundworms and mice.

The target of rapamycin, mTORC1 (this explains the name of the protein, the kinase subunit of the complex – mTOR, mammalian target of rapamycin, the target of rapamycin in mammals), is a regulator of cell proliferation, controlling, among other things, the rate of cell division and the rate of protein synthesis. In addition, as has been established in previous studies, this signaling complex controls the expression of key synaptic proteins in the brain associated with learning and memorization. Thus, blocking mTORC1, among other things, leads to a violation of this mechanism.

As for alcoholism, then, as in the case of other addictions, it is known that the circumstances associated with taking a drink – taste, smell, environment, sounds, and so on - play a huge role in the formation of addiction, and it is extremely difficult to get rid of these associations, which are triggers of relapse.

The authors of the study turned laboratory rats into chronic alcoholics, giving them the opportunity to choose between water and a 20 percent mixture of water and alcohol by pressing a lever for seven weeks. As the authors note, in the end, all the animals preferred an alcoholic mixture. By the end of the seven-week period, the alcohol concentration in their blood reached 80 milligrams per 100 milliliters of blood.

Then the rats were deprived of their favorite drink for ten days, and after that time, a tiny drop of it was dropped into the mouth of each of the animals, just to remind them of the taste and smell. Immediately after the occurrence of such an alcohol-associated memory, some rats received rapamycin.

It was found that after the "reminder" in animals, mTORC1 was sharply activated in various regions of the brain (tonsils and cortex), and under the action of rapamycin, this activity significantly decreased. As a result, those rats who were given rapamycin, unlike the rest, did not even approach the lever during the control two-week period to try to get an alcoholic mixture.

The authors believe that rapamycin does not affect the formation of new memories, but interferes with the process of fixing existing ones in long-term memory after their reactivation. Although rapamycin has many side effects, the authors hope that over time they will be compensated and this drug can still be used to prevent relapses of alcohol dependence.

Portal "Eternal youth" http://vechnayamolodost.ru24.06.2013