Scientists and experts have been showing a lot of interest in recent times in the chemicals and the pathways of the brain responsible for triggering drug-seeking behavior among many.Among the various chemicals and pathways, there has been a growing interest in the role of the infralimbic cortex. Apparently, infralimbic cortex, which is responsible for inhibiting emotional response by triggering self-control, plays a key role in cocaine addiction.
By enabling a person to express and acquire an ongoing habitual behavior, infralimbic cortex can exacerbate addiction. The neurobiological evidences suggest that loss of such behavioral flexibility is witnessed in the case of addiction. Besides initiating cocaine-seeking behavior, infralimbic cortex enables the inhibition of drug-seeking behavior by extinction learning.
Cocaine is a notorious stimulant that produces a high, known as cocaine intoxication. The desire to experience this high is the primary reason why most people start using cocaine. Drug peddlers often mix cocaine powder with cornstarch, talcum powder, flour or amphetamines to maximize profits.
According to the results of 2015 National Survey on Drug Use and Health (NSDUH), about 1.9 million individuals aged 12 or older were the current users of cocaine. Of them, about 394,000 were the current users of crack cocaine. Similarly, about 896,000 individuals age 12 or older had a cocaine use disorder in the past year.
Compared to other drugs, cocaine can induce both short- and long-term psychological changes that affect the way the users think and experience emotions. This occurs as a result of cocaine's interaction with the brain and the nervous system. Although cocaine use generates euphoric effects as witnessed in the case of other drugs, this experience differs invariably from person to person.
Considering the level of repercussions of cocaine intoxication, it becomes more important to understand the ways to alleviate this problem.A research published in the Journal of Neuroscience demonstrated that the activity in the infralimbic cortex of lab rats inhibited cocaine-seeking behaviors. These findings have widened the scope of treating addictive behaviors in the future.
Diminishing cravings by muting neurons in infralimbic cortex
The infralimbic cortex is located in the ventromedial prefrontal cortex, a brain region responsible for inhibition of emotional responses and self-control.
The researchers from the University of Iowa (UI) sought to find out more about the unique relationship between this subregion of the brain and cocaine-seeking behaviors. The team led by Andrea Gutman, a postdoctoral researcher in the Department of Psychological and Brain Sciences of the UI, assessed the possibilities of manipulating the functions of the infralimbic cortex to regulate impulsive behaviors.
The study entailed two groups of rats as control and experimental that were administered cocaine using a lever. The access of the lever was available for two hours per day for two weeks. After two weeks, the rats in the control group were not provided cocaine.Over the course of another two weeks, the rats became accustomed to the fact that there was no cocaine reward and completely stopped pressing the lever at the end of this period. They had learned to restrain their cravings.
The experimental group of rats not only went through the same routine, but also the additional activity wherein the researchers deactivated the infralimbic cortex of the rats for 20 seconds for each time they pressed the lever.This was done by muting the infralimbic cortex with the gamma-amino butyric acid (GABA) agonist. As a result, they did not learn to restrain their cravings and continued to press the lever till the end of the two-week phase despite not receiving the cocaine reward.
The researchers found the following correlations:
- The experimental group of rats was more likely to relapse compared to the control group.
- Activity in the infralimbic cortex when the rats expected a reward was important in reducing the substance-seeking behavior.
“While our experiments involved cocaine, we think the results could hold true for the infralimbic cortex's role in conditioning withdrawal and relapse from other addictive substances, including opioids,” said co-author Ryan LaLumiere, an assistant professor in UI's Department of Psychological and Brain Sciences.The findings suggest that medications designed to mute neurons in the infralimbic cortex at the time of the expected reward can hold the secrets of curbing addictive behaviors in the future.
Path to recovery
The repeated exposure to cocaine alters the brain's reward pathways that makes it dependent on the substance.Over time, stress circuits become more sensitive that leads to increased displeasure and negative mood when not on the drug, displaying the first symptoms of withdrawal and other health complications. Therefore, it is essential to learn the ways to identify the warning signs and share one's fears to an expert to avoid the worsening of his or her condition.