A new study has revealed that in people with cocaine use disorder, one of the most popular drugs, They register changes at the brain level at an accelerated rate.
As collected Science Alertcocaine is one of the most addictive substances known to humans. interferes with reward pathways in the brainforcing your cells to continue pumping out pleasurable signals until the drug wears off.
How a drug that interferes with the junctions between brain cells evokes addictive behaviors that in turn manifest in substance abuse is a chain of events that researchers they are still trying to understand.
One possibility lies in non-coding modifications made to the DNA packaged inside brain cells, altering the way their genes are turned on and off. So the research looked at the patterns of these so-called epigenetic changes in a region of the brain called Brodmann area 9.
Located in the prefrontal cortex, the front part of the brain that rests behind the forehead, Brodmann Area 9 (BA9) is believed to be important for self-awareness and inhibitory controltwo things that are confused in substance use disorders.
Much of what we know about what cocaine does to brain cells comes from studies in mice. Little research has examined the long-lasting effects of cocaine on human brain tissue, although two studies to date have detected regions of DNA showing excessive methylation in the brains of people addicted to cocaine.
This new study on human brain tissue recovered post-mortem found the same thing again: In BA9, cocaine users had sections of DNA scalloped with methyl groups, chemical changes that have been found to accumulate with age and in age-related diseases.
To arrive at these results, the researchers compared the levels of DNA methylation in brain tissue samples from 21 people who had cocaine use disorder and another 21 that do not.
DNA methylation is considered one of the molecular characteristics of aging. Usually, the presence of more methyl groups reduces the activity of nearby genes because the cell’s machinery can no longer access the genetic instructions contained within.
Knowing how methyl groups were attached to DNA over time, DNA methylation can be used as a an “epigenetic clock” to see if tissues age faster or slower compared to their expected chronological age.
In this study, the researchers used two epigenetic clocks different to try to explain any variation.
“We detected a trend toward stronger biological aging of the brain in people with cocaine use disorder compared to people without cocaine use disorder,” he says. Stephanie Wittlead author of the study and a molecular biologist at the Central Institute for Mental Health in Germany.
“This could be caused by cocaine-related disease processes in the brain, such as inflammation or cell deathWitt adds.
The researchers believe that these molecular alterations may contribute to the high-level functional and structural changes seen in the brains of people with cocaine use disorder and, in turn, to the behavioral aspects of addiction.
Among the sequences that showed the strongest changes in DNA methylation in this study were two genes that, according to previous research, regulate behavioral aspects of cocaine intake in rodents.
However, the researchers acknowledge that their study was small and more research is required, perhaps to see what molecular changes the brain accumulates over time with continued drug use.
“Since biological age estimation is a very recent concept in addiction research and is influenced by many factors, further studies are required to investigate this phenomenonwith larger sample sizes than possible here,” says Witt.
Larger studies would also help separate the effects of other conditions, such as mood disorders, that so often accompany substance use disorders. Many of the deceased donors in this study suffered from major depression which may have altered your brain function in other ways.
The researchers also noted whether the donors were intoxicated when they died or if they had been using drugs to treat depression or other conditions, although the study was too small to adjust for this.
However, it builds on previous studies of other brain regions to expand our knowledge of how drug addiction can intrude on the brain.
“Looking at multiple brain regions allows a fuller understanding” of the role of DNA methylation in cocaine use disorder, the researchers conclude.