Frequent abuse of cocaine alters gene expression in the hippocampus, according to research in mice recently published in JNeurosci.
Chronic drug users over time learn to associate the drug-taking environment with the drug itself, reinforcing memories that lead to addiction. These memories are reportedly created by changes in gene expression in the hippocampus and potentially even the gene FosB has an involvement. However, the exact mechanism is unknown.
A.J. Robinson and co-researchers at Michigan State University analyzed how cocaine exposure led to an expression of the FosB gene in the hippocampus. Mice that were administered cocaine daily displayed the increasingly overt expression of FosB compared to mice that received saline.
Chronic cocaine use caused epigenetic alteration of the gene, allowing it to become more active. Also, when the scientists blocked the changes made to FosB, the mice were not able to create associations between cocaine and the environment where they had received it, suggesting epigenetic guidelines of the gene in drug memory formation.
These results show new insight into the molecular alterations that take place in the hippocampus during intense cocaine use. Additional research in this area could lead to the development of addiction therapies.
Deaths due to cocaine nearly doubled from 5,892 in 2014 to 11,316 in 2016, said a 2018 report from the Centers for Disease Control and Prevention.
Despite the study, the researchers think that by ‘short-circuiting’ the gene and protein that form the memory of cocaine feel so good, they might aid in breaking the pattern of addiction as well.
The study and related research were fully funded by the National Institute on Drug Abuse and the National Institute of Mental Health.
The research has been published in the Journal of Neuroscience.