Does Cocaine Permanently Rewire the Brain for Addiction?

A recent study has found that chronic use of cocaine can lead to a reduction in brain plasticity, or in other words, can permanently alter your brain to become more susceptible to addiction. 

The study, which was published last month in the journal Nature Neuroscience, which was conducted in tandem by the University of Buffalo and the Mount Sinai School of Medicine, used mice to examine the effect that cocaine use has on the brain’s reward system, and how that relationship plays into the propensity for addiction and relapse.

The experiment itself used a tool never before employed in studies pertaining to brain plasticity: a modified protein that is activated when exposed to light.  Now that the protein in question (in this case, Rac1, a signaling protein that regulates cell growth, cytoskeletal reorganization, and the activation of certain protein kinases, or proteins that transmit signals to other proteins which then control various processes in cells) was quantifiable, the researchers subjected the mice to various amounts of cocaine and measured the corresponding presence of the protein. 

What they found was a strong correlation between chronic cocaine use (not necessarily heavy use) and a decreased expression of the protein Rac1. The decreased amount of Rac1 created a “cascade of events” that ultimately resulted in a reduction in the plasticity of the brain… or in other words, more frequent cocaine use caused the brain to become less malleable. 

If losing the ability for your brain to generally change (and essentially heal itself) wasn’t bad enough news, researchers also noted a significant increase in the number of spines that protruded out from neurons in the reward center of the brain.  In other words, the brain’s reward system rewires itself to become more receptive to the euphoric effects of cocaine, which strongly suggests that one would be more susceptible to the addicted state.

However, there is hope.  Researchers were able to alter the level of expression of Rac1, which allowed them to effectively control the mice’s level of addiction when exposed to cocaine.  Not only does this look promising in terms of nullifying a reduction in brain plasticity, but may prove to be able to even reverse damage done on the bains of former or current addicts.  Although the study of a modified protein kinases in regards to cocaine addiction is the first of its kind, the methodology employed looks to have a bright future in studies on other disorders that involve the reward system of the brain, such as obsessive compulsive disorder and panic attacks. 

Eric Hirota is a freelance writer and blogger for various healthcare websites.