How Substance Abuse Can Cause Irreversible Brain Changes

A recent study highlights how substance use can lead to cognitive decline and irreversible changes in the brain.

Highlights:

Cognitive flexibility is the ability of the brain to adapt and switch between various tasks
A recent study highlights the role of cocaine and alcohol abuse in reducing cognitive flexibility //
The authors are hopeful that this insight will help in the development of new therapeutics even though further research is required

About 50 million people in the United States struggle with cocaine addiction or alcohol use disorders ().

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‘A new study provides new insight into the role of substance abuse on cognitive flexibility #substanceabuse’

Substance Abuse Affects the Our Cognitive Flexibility and Quality of Life

In addition to the well-known health hazards, addiction to these substances harms our cognitive flexibility, or our capacity to change and transition between various tasks or tactics. Although earlier research suggested a link, the exact causes of this cognitive impairment are yet unknown.

In many areas of our lives, including academic accomplishment, professional success, and the transition to adulthood, cognitive flexibility is essential. This adaptability is crucial in preventing cognitive deterioration as we age. However, a lack of cognitive flexibility is associated with poorer academic performance and a worse quality of life.

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Substance Abuse Affects Neurons

A ground-breaking investigation headed by Dr. Jun Wang, an associate professor in the Texas A&M University School of Medicine's Department of Neuroscience and Experimental Therapeutics, sheds new light on the detrimental effects that prolonged cocaine or alcohol use has on cognitive flexibility.

The study, which was published in the journal Nature Communication, focuses on how the local inhibitory brain circuit mediates the harmful consequences of substance abuse on cognitive flexibility.

Substance usage affects a subset of neurons known as striatal direct-pathway medium spiny neurons (dMSNs), which project to the substantia nigra pars reticulata (SNr). Conversely, striatal cholinergic interneurons (CINs) increase cognitive flexibility by receiving powerful inhibitory signals from the striatum ().

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The Relationship Between Substance Abuse, dMSNs, and CINs

“We hypothesized that increased dMSN activity from substance use inhibits CINs, leading to a reduction in cognitive flexibility,” Wang said.

“Our research confirms that substance use induces long-lasting changes in the inhibitory communication between dMSNs and CINs, consequently dampening cognitive flexibility. Furthermore, the dMSN-to-SNr brain circuit reinforces drug and alcohol use, while the associated collateral dMSN-to-CIN pathway hinders cognitive flexibility. Thus, our study provides new insights into the brain circuitry involved in the impairment of cognitive flexibility due to substance use.”

Wang and his team are optimistic about the potential therapeutic applications of their findings and anticipate that they could inform new treatment strategies for substance-induced cognitive decline.

Reference:

NIDA IC Fact Sheet 2023 - (https://nida.nih.gov/about-nida/legislative-activities/budget-information/fiscal-year-2023-budget-information-congressional-justification-national-institute-drug-abuse/ic-fact-sheet-2023)
Drug reinforcement impairs cognitive flexibility by inhibiting striatal cholinergic neurons - (https://www.nature.com/articles/s41467-023-39623-x)

Source-Medindia

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