Our brains undergo changes as we age. A new study has revealed that in people with cocaine addiction problems, these changes happen at a faster rate.
Cocaine is one of the most addictive substances, interfering with the brain’s reward pathways and forcing cells to pump out pleasant signals until the drug wears off. US estimates, reported the Science Alertsuggest that one in five people who use cocaine develop an addiction.
How cocaine evokes addictive behaviors by interfering with brain cells, which in turn create substance abuse, is a chain of events that researchers are still trying to understand.
One possibility lies in non-coding changes made to DNA within brain cells, which alter the way their genes are turned on and off. In this investigation, the team analyzed the patterns of these epigenetic changes in a brain region designated by Brodmann’s Area 9 (BA9) .
Located in the prefrontal cortex – the front part of the brain, behind the forehead – BA9 is believed to be essential for self-awareness and inhibitory control; two things that get confused when there is substance use.
Much of what is known about cocaine’s effects on brain cells comes from studies in rats. Few investigations have analyzed the long-lasting effects of cocaine on human brain tissue. Two studies have found regions of DNA that show excessive methylation in the brains of people with addiction.
In this new study, recently published in Frontiers in Psychiatryresearchers analyzed human brain tissue recovered post-mortem, having found the same pattern: Cocaine users had sections of DNA festooned with methyl groups at BA9.
These reactions are chemical changes that accumulate with age and in age-related diseases.
To arrive at these results, the researchers compared DNA methylation levels in brain tissue samples from 21 people who had cocaine disorders and 21 who did not.
DNA methylation is considered one of the molecular marks of aging. Typically, the presence of more methyl groups decreases the activity of nearby genes because the cell’s machinery can no longer access the genetic instructions contained within.
By knowing how methyl groups attach to DNA over time, DNA methylation can be used as an “epigenetic clock” to see whether tissues age faster or slower compared to chronological age.
In this study, the researchers used two epigenetic clocks different to account for variations.
“We detected a trend towards stronger biological aging in the brain in individuals with a cocaine use disorder compared to individuals without the disorder,” said Stephanie Witt, one of the study’s authors and a molecular biologist at the Central Institute of Mental Health in Germany. .
“This could be caused by cocaine-related brain disorders such as inflammation or cell death,” he continued.
The researchers believe that these molecular changes may contribute to the high-level functional and structural changes observed in the brain of people with cocaine dependence and, in turn, for the behavioral aspects of drug addiction.
Among the sequences that showed the strongest changes in DNA methylation in this study were two genes that, according to previous investigations, regulate the behavioral aspects of drug ingestion in rats.
However, the researchers acknowledge that their study was small and that more research is needed.
“Such as Biological age estimation is a very recent concept in addiction research and is influenced by many factors, more studies are needed to investigate this phenomenon, with larger samples”, indicated Stephanie Witt.
Larger studies would also help rule out the effects of other conditions, such as mood disorders, which often accompany substance use disorders. Many of the deceased donors in this study suffered from depression, which may have altered their brain function in other ways.
The researchers also took into account whether the donors were intoxicated when they died or if they had used medication to treat depression or other conditions.
ZAP // 
