MRI scans on rat brains could lead to new cocaine addiction therapies
Quitting cocaine after long-term use can cause severe brain fog that drives users back to the drug in order to get through the day, and now researchers working with rat models may better understand why it becomes addictive over time.
Scientists at the UNC School of Medicine found that prolonged cocaine use affects how neural networks communicate, including the default mode network (DMN), the salience network (SN), and the lateral cortical network (LCN), ultimately reducing the brain’s ability to solve problems and complete tasks. The findings are published in the Journal of Neuroscience. [1]
“The disrupted communication between the DMN and SN can make it harder to focus, control impulses, or feel motivated without the drug,” Li-Ming Hsu, PhD, assistant professor of radiology at UNC School of Medicine and lead author on the study said in a statement. “Essentially, these changes can impact how well they respond to everyday situations, making recovery and resisting cravings more challenging.”
Hsu said this study improves the body of knowledge surrounding cocaine addiction on a physiological level, and the findings present opportunity for the development of therapeutic interventions and the identification of an imaging marker for cocaine abuse.
While this research was conducted on rats, it was inspired by previous imaging studies on the human brain that showed chronic cocaine use disrupts connectivity within and between key brain networks. Hsu and his colleagues sought to build on that research to understand more specifically what happens to the brain during withdrawal.
Utilizing a rat model that mimics human addictive behaviors—where rats self-administer cocaine through their nose—the study lasted for a 10-day period of use, followed by withdrawal. The researchers then deployed MRI scans to develop a comprehensive understanding of how prolonged cocaine use gradually reshapes the brain’s neural pathways.
The research team observed significant changes in network communication, particularly between the default mode network and salience network. These changes became more pronounced with higher levels of cocaine intake during the 10-day self-administration period, indicating a potential target for mitigating cocaine cravings and supporting recovery efforts. Further, alterations in communication within these networks could serve as valuable imaging markers for diagnosing cocaine addiction.
The research also provided fresh perspectives on the roles of the anterior insular cortex, responsible for emotions, and retrosplenial cortex, which regulates memory and navigation. Hsu and his team observed variations in the coordinated activity of these regions both pre- and post-cocaine consumption, which may explain behavioral shifts associated with cocaine use disorders.
“Prior studies have demonstrated functional connectivity changes with cocaine exposure; however, the detailed longitudinal analysis of specific brain network changes, especially between the anterior insular cortex and retrosplenial cortex, before and after cocaine self-administration, and following extended abstinence, provides new insights,” Hsu added.
More research is necessary—particularly on humans—to validate the findings before new treatments can be developed.
The full study is available at the link below.
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