Recently researchers at the University at Buffalo published interesting findings concerning opiates effects on the brain. The research gets down to the molecular level but has important real world implications for the treatment of opiate addiction.
Before diving into the research it's relevant to review some brain anatomy and biochemistry and opiates effects on these systems. I realize I may have lost many readers after that sentence, but if you’re still there this will be brief and useful.
Synapse with messenger neurotransmitters. Credit: teachmephysiology.com
The building block cell of the brain is known as the neuron. This cell is designed to carry out one of the prime functions of the brain which is to manage and transmit information. The neuron does this by releasing chemicals known as neurotransmitters. The neurotransmitters flow from one neuron to another across the space between neurons known as the synapse and are received at the other neuron on specialized projections called receptors. Drugs that affect the brain often work by affecting how these neurotransmitters work, either by imitating them or blocking them at receptors.
Opiates work by binding to the aptly named opiate receptor. When this happens it sends a signal to the neuron to release more of the neurotransmitter dopamine. Dopamine is involved in a variety of functions in the brain, one of which is its role in pleasure pathways. Dopamine contributes to feelings of pleasure and satisfaction and thus the euphoria associated with opiates.
So for anyone familiar with the saying “30,000 foot view” this description equates to a view from Mars but will suffice for understanding the research from Buffalo. So what did the team in Buffalo find? That opiates (specifically heroin in their study) reduce a brain protein called drebin that is responsible for upkeep of the synapses (the spaces in between cells where messages in the brain are relayed, in case you skipped over the first part of this blog). This protein, or rather the lack of it, has been found in other brain diseases such as Alzeihmers.
The loss of this protein happens in a part of the brain known as the nucleus accumbens. This area of the brain is involved with reward, and the perception of positive outcomes.
Ok so why does all this matter? The team at Buffalo found that if you can replace the drebin back to normal levels you can reduce relapse behavior. This team specifically looked at rats but presumably these findings would be applicable to people. It’s possible to imagine novel treatments for opiate addiction in the future using these findings.
This blog touches on just a small portion of this team's interesting findings. The title in the citation below contains a link to the full article for those who are interested.
Reference
Martin, JA et al. A novel role for the actin-binding protein drebin in regulating opiate addiction. Nature Communications, 2019; 10(1)