Scientists discover a novel opiate addiction switch in the brain

Neuroscientists at Western University (London, Canada) have made a remarkable new discovery revealing the underlying molecular process by which opiate addiction develops in the brain. Opiate addiction is largely controlled by the formation of powerful reward memories that link the pleasurable effects of opiate-class drugs to environmental triggers that induce drug craving in individuals addicted to opiates. The research is published in the September 11th issue of The Journal of Neuroscience.

The Addiction Research Group led by Steven Laviolette of the Schulich School of Medicine & Dentistry was able to identify how exposure to heroin induces a specific switch in a memory molecule in a region of the brain called the basolateral amygdala, which is involved importantly in controlling memories related to opiate addiction, withdrawal, and relapse. Using a rodent model of opiate addiction, Laviolette's team found that the process of opiate addiction and withdrawal triggered a switch between two molecular pathways in the amygdala controlling how opiate addiction memories were formed. In the non-dependent state, they found that a molecule called extracellular signal-related kinase or "ERK" was recruited for early stage addiction memories. However, once opiate addiction had developed, the scientists observed a functional switch to a separate molecular memory pathway, controlled by a molecule called calmodulin-dependent kinase II or "CaMKII".

"These findings will shed important new light on how the brain is altered by opiate drugs and provide exciting new targets for the development of novel pharmacotherapeutic treatments for individuals suffering from chronic opiate addiction," says Laviolette, an associate professor in the Departments of Anatomy & Cell Biology, Psychiatry, and Psychology.

More information: The paper is titled "Opiate Exposure and Withdrawal Induces a Molecular Memory Switch in the Basolateral Amygdala Between ERK1/2 and CaMKII-Dependent Signaling Substrates."

Related Stories

Radical solution to ‘clip’ addiction

Aug 08, 2011

Accidentally leaving a stainless-steel spatula in an overnight experiment has led to the discovery of a more efficient and environmentally friendly method of producing anti-addiction medications.

New insight into how brain 'learns' cocaine addiction

Aug 01, 2013

A team of researchers says it has solved the longstanding puzzle of why a key protein linked to learning is also needed to become addicted to cocaine. Results of the study, published in the Aug. 1 issue of the journal Cell, descri ...

Heroin availability increasing across Washington state

Jun 12, 2013

New data from the University of Washington's Alcohol and Drug Abuse Institute indicates increases in heroin availability, abuse and deaths across the state, particularly among young adults ages 18-29. These increases are ...

Early warning of newborn withdrawal

Jul 02, 2013

In substance-exposed newborns, identification of the gene variations associated with risk of opioid addiction could aid the treatment of their withdrawal symptoms in the critical hours after birth, according ...

Recommended for you

'Chatty' cells help build the brain

10 hours ago

The cerebral cortex, which controls higher processes such as perception, thought and cognition, is the most complex structure in the mammalian central nervous system. Although much is known about the intricate ...

'Trigger' for stress processes discovered in the brain

Nov 27, 2014

At the Center for Brain Research at the MedUni Vienna an important factor for stress has been identified in collaboration with the Karolinska Institutet in Stockholm (Sweden). This is the protein secretagogin ...

New research supporting stroke rehabilitation

Nov 26, 2014

Using world-leading research methods, the team of Dr David Wright and Prof Paul Holmes, working with Dr Jacqueline Williams from the Victoria University in Melbourne, studied activity in an area of the brain ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.