A Look at the Brain Circuitry of Addiction

A Look at the Brain Circuitry of Addiction

Cravings and urges to use alcohol or drugs can make recovery feel challenging. Although short-lived, cravings are a major contributing factor in potential relapses after a period of abstinence from drugs and alcohol. Learn more about how the brain plays a role in addiction and how to build strength for recovery.

 

Brain Circuitry of Addiction

Everyone’s brains are wired differently but reward and motivation centers of the brain are the same for everyone. The release of dopamine plays a role in addiction and drug use. Pavlov’s classical conditioning approach has been used to explain behavioral motivation to use drugs or alcohol for a long time. Cravings can result from repeated pairing, according to the study, of certain environmental or external cues (people, places, sounds) even when the drug is not present. With repeated pairing of a cue with a reward, the motivation center of the brain seeks to obtain the reward. The desirable object doesn’t need to be present for triggers to occur which explains why people use drugs after long periods of abstinence.

 

Incentive Sensitization Theory

The incentive sensitization theory suggests an incentive salience is a relatively unconscious process involving highly sensitized neural systems such as the mesocorticolimbic brain system. The pairing of an external stimulus cue with drug use primes a person to seek out more of the reward, further amplified by certain neurobiological and physiological states and other brain changes induced by repeated drug use over time.

 

DREADDs

Researchers are using new technology called designer receptors activated by designer drugs (DREADDs) to repeatedly disrupt the ventral pallidum, a part of the brain involved in conditioned and unconditioned reward-seeking behaviors. The drugs are used to repeatedly disrupt ventral pallidum activity in rats. Some rats attribute strong incentive salience to a conditioned stimulus cue (metal lever inserted into a chamber) which predicts  reward (food, for instance). Sign-trackers are more likely to approach the metal lever and sniff or nibble when it appears associated with a reward. Following inactivation of the ventral pallidum, researchers inserted a lever into the experimental chamber for 10 seconds, followed by a food pellet reward when lever was withdrawn. Food was given to the rats regardless of behavior but the sign-tracker rats pressed the lever and bit it as if it were the reward itself.

By injecting clozapine N-oxide (CNO) into the ventral pallidum, researchers were able to suppress activity of the ventral pallidum and block the rats’ sign-tracking behavior (lever pressing) which led to the conclusion that inactivation of the ventral pallidum during ‘sign-tracking’ disrupted the transfer of incentive value to obtain the reward. The ventral pallidum, in other words, plays a key role in motivational behaviors underlying drug addiction.

People in recovery face triggers which motivate individuals to use even after prolonged periods of abstinence and sobriety. Identifying and managing triggers to avoid relapse is a key part of recovery.

 

Hired Power seeks to help individuals with addiction build strength and resilience in recovery. Call us to find out how we can help you break through the cycle of addiction.