November 2011 New studies show that microRNAs, snippets of RNA implicated in a wide variety of biological processes, are involved in promoting and inhibiting cocaine addiction. The findings could pave a new path for the development of anti-addiction therapies.
A brain response occurs in the nucleus accumbens when rats encounter a cue that they associate with previous cocaine self-administration, but not a cue associated with a pleasurable non-drug experience. Moreover, the response correlates in time and intensity with the animals’ cue-induced relapse to cocaine-seeking.
Nicotine sensitizes the mouse brain to the addictive effects of cocaine, according to recent NIDA-supported research. The results accord with the hypothesis that a person’s initial use of an addictive substance physiologically sensitizes his or her brain to the rewarding and addictive effects of other substances. If the findings carry over to people, then preventing youths from smoking might reduce their vulnerability to cocaine abuse and addiction, and cocaine-dependent individuals might ease their path to recovery by quitting smoking.
Reports on research showing that the neurons that deliver dopamine to two regions of the brain's mesolimbic reward system respond differently to opioids, an important finding for drug treatment research.