Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Addiction relapse might be thwarted by turning off brain trigger

25.06.2013
UCSF study points to potential strategy for erasing memory of addiction

A new study by researchers at the Ernest Gallo Clinic and Research Center at UC San Francisco offers encouraging findings that researchers hope may one day lead to a treatment option for people who suffer from alcohol abuse disorders and other addictions.

In the study, conducted in rats, the UCSF researchers were able to identify and deactivate a brain pathway linked to the memories that cause cravings for alcohol, thus preventing the animals from seeking alcohol and drinking it, the equivalent of relapse.

"One of the main causes of relapse is craving, triggered by the memory by certain cues - like going into a bar, or the smell or taste of alcohol," said lead author Segev Barak, PhD, at the time a postdoctoral fellow in the lab of co-senior author Dorit Ron, PhD, a Gallo Center investigator and UCSF professor of neurology.

"We learned that when rats were exposed to the smell or taste of alcohol there was a small window of opportunity to target the area of the brain that reconsolidates the memory of the craving for alcohol and to weaken or even erase the memory, and thus the craving" he said.

The study, also supervised by co-senior author Patricia H. Janak, a Gallo Center investigator and UCSF professor of neurology, will be published online on June 23, 2013 in Nature Neuroscience.

In the first phase of the study, rats had the choice to freely drink water or alcohol over the course of seven weeks, and during this time developed a high preference for alcohol. In the next phase, they had the opportunity to access alcohol for one hour a day, which they learned to do by pressing a lever. They were then put through a 10-day period of abstinence from alcohol.

Following this period, the animals were exposed for 5 minutes to just the smell and taste of alcohol, which cued them to remember how much they liked drinking it. The researchers then scanned the animals' brains, and identified the neural mechanism responsible for the reactivation of the memory of the alcohol - a molecular pathway mediated by an enzyme known as mammalian target of rapamycin complex 1 (mTORC1).

They found that just a small drop of alcohol presented to the rats turned on the mTORC1 pathway specifically in a select region of the amygdala, a structure linked to emotional reactions and withdrawal from alcohol, and cortical regions involved in memory processing.

They further showed that once mTORC1 was activated, the alcohol-memory stabilized (reconsolidated) and the rats relapsed on the following days, meaning in this case, that they started again to push the lever to dispense more alcohol.

"The smell and taste of alcohol were such strong cues that we could target the memory specifically without impacting other memories, such as a craving for sugar," said Barak, who added that the Ron research group has been doing brain studies for many years and has never seen such a robust and specific activation in the brain.

In the next part of the study, the researchers set out to see if they could prevent the reconsolidation of the memory of alcohol by inhibiting mTORC1, thus preventing relapse. When mTORC1 was inactivated using a drug called rapamycin, administered immediately after the exposure to the cue (smell, taste), there was no relapse to alcohol-seeking the next day. Strikingly, drinking remained suppressed for up to 14 days, the end point of the study. These results suggest that rapamycin erased the memory of alcohol for a long period, said Ron.

The authors said the study is an important first step, but that more research is needed to determine how mTORC1 contributes to alcohol memory reconsolidation and whether turning off mTORC1 with rapamycin would prevent relapse for more than two weeks.

The authors also said it would be interesting to test if rapamycin, an FDA-approved drug currently used to prevent organ rejection after transplantation, or other mTORC1 inhibitors that are currently being developed in pharmaceutical companies, would prevent relapse in human alcoholics.

"One of the main problems in alcohol abuse disorders is relapse, and current treatment options are very limited." Barak said. "Even after detoxification and a period of rehabilitation, 70 to 80 percent of patients will relapse in the first several years. It is really thrilling that we were able to completely erase the memory of alcohol and prevent relapse in these animals. This could be a revolution in treatment approaches for addiction, in terms of erasing unwanted memories and thereby manipulating the brain triggers that are so problematic for people with addictions."

The other co-authors of the paper are Feng Liu, PhD, Sami Ben Hamida, PhD, Quinn V. Yowell BS, Jeremie Neasta, PhD, and Viktor Kharazia, PhD, all of the Gallo Center and UCSF Department of Neurology.

The study was supported by funds from the National Institute on Alcohol Abuse and Alcoholism and funds from the State of California for Medical Research on Alcohol and Substance Abuse administered through UC San Francisco.

The UCSF-affiliated Ernest Gallo Clinic and Research Center is one of the world's preeminent academic centers for the study of the biological basis of alcohol and substance use disorders. Gallo Center discoveries of potential molecular targets for the development of therapeutic medications are extended through preclinical and proof-of-concept clinical studies.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.

Jeffrey Norris | EurekAlert!
Further information:
http://www.ucsf.edu

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>