Cocaine Relapse is Reversed With BDNF Microinjections in The Brain
Source: Medical University of South Carolina
Summary: Investigators reported that cocaine relapse was significantly reduced in a preclinical model when brain-derived neurotropic factor (BDNF) was applied to the nucleus accumbens deep in the brain immediately before cocaine-seeking behavior.
The nucleus accumbens is a tiny cluster of nerve cells deep in the brain. Although small, this region plays a critical role in reward-seeking behaviors. The nucleus accumbens combines signals from other parts of the brain to drive reward-motivated behaviors. The MUSC research group is the first to reveal that BDNF has both a time- and location-dependent beneficial role when administered before a cue-induced relapse event. Addiction researchers are studying the function of proteins already present in the brain in an effort to find ways to overcome relapse in strong addictions. Investigators from the Medical University of South Carolina reported that cocaine relapse was significantly reduced in a preclinical model when brain-derived neurotropic factor (BDNF) was applied to the nucleus accumbens deep in the brain immediately before cocaine-seeking behavior. The study findings were published in the journal Addiction Biology.
In the preclinical model of cocaine addiction, rats are allowed to self-administer cocaine while hearing an auditory cue. The rats learn to associate the cue with the reward of cocaine and continue to self-administer when hearing the cue. In the extinction phase, the rats are not allowed access to cocaine or the cue associated with the drug. In the last phase, called reinstatement, the rats seek out cocaine upon hearing the cue previously associated with cocaine administration. The drug-seeking behavior that the rats display is similar to how drug cues induce craving in humans and thus are more likely to relapse. Examples of such cues are visiting a neighborhood in which drugs were previously bought or seeing a friend with whom they took drugs. The findings reported in Addiction Biology are the first to show that applying BDNF to the nucleus accumbens immediately before the reinstatement phase, when the rats are once again seeking cocaine due to cue exposure, greatly reduces relapse.
Lead author Ana-Clara Bobadilla said, “What we are doing with these studies is mapping the brain. There are plenty of uncharted territories in our understanding of neurobiology and with this work we provided results to fill in one of those unknown questions.”
More Information: Ana-Clara Bobadilla et al, “Accumbens brain-derived neurotrophic factor (BDNF) transmission inhibits cocaine seeking”, Addiction Biology (2018)Addiction Biology. DOI: 10.1111/adb.12638