Navigation Links
Morphine makes lasting -- and surprising -- change in the brain

Morphine, as little as a single dose, blocks the brain’s ability to strengthen connections at inhibitory synapses, according to new Brown University research published in Nature.

The findings, uncovered in the laboratory of Brown scientist Julie Kauer, may help explain the origins of addiction in the brain. The research also supports a provocative new theory of addiction as a disease of learning and memory.

"We’ve added a new piece to the puzzle of how addictive drugs affect the brain," Kauer said. "We’ve shown here that morphine makes lasting changes in the brain by blocking a mechanism that’s believed to be the key to memory making. So these findings reinforce the notion that addiction is a form of pathological learning."

Kauer, a professor in the Department of Molecular Pharmacology, Physiology and Biotechnology at Brown, is interested in how the brain stores information. Long-term potentiation, or LTP, is critical to this process.

In LTP, connections between neurons ?called synapses, the major site of information exchange in the brain ?become stronger after repeated stimulation. This increased synaptic strength is believed to be the cellular basis for memory.

In her experiments, Kauer found that LTP is blocked in the brains of rats given as little as a single dose of morphine. The drug’s impact was powerful: LTP continued to be blocked 24 hours later ?long after the drug was out of the animal’s system.

"The persistence of the effect was stunning," Kauer said. "This is your brain on drugs."

Kauer recorded the phenomenon in the ventral tegmental area, or VTA, a small section of the midbrain that is involved in the reward system that reinforces survival-boosting behaviors such as eating and sex ?a reward system linked to addiction. The affected synapses, Kauer found, were those between inhibitory neurons and dopamine neurons. In a healthy brain, inhibitory cells would limit the release of dopamine, the "pleasure chemical" that gets released by naturally rewarding experiences. Drugs of abuse, from alcohol to cocaine, also increase dopamine release.

So the net effect of morphine and other opioids, Kauer found, is that they boost the brain’s reward response. "It’s as if a brake were removed and dopamine cells start firing," she explained. "That activity, combined with other brain changes caused by the drugs, could increase vulnerability to addiction. The brain may, in fact, be learning to crave drugs."

Kauer and her team not only recorded cellular changes caused by morphine but also molecular ones. In fact, the researchers pinpointed the very molecule that morphine disables ?guanylate cyclase. This enzyme, or inhibitory neurons themselves, would be effective targets for drugs that prevent or treat addiction.
'"/>

Source:Brown University


Related biology news :

1. Morphine for Chest Pain Increases Death Risk
2. University of Manchester makes made-to-measure skin and bones a reality using inkjet printers
3. Grass makes environmentally friendly biofuel
4. Shampoo detergent added to paint makes surfaces self-sterilizing
5. Biota makes major antiviral discovery
6. Green diesel: New process makes liquid transportation fuel from plants
7. Discovery that bacterium is phosphate gourmet key clue to what makes it most social of bacteria
8. Technique makes it easier to see mouse embryo in all its glory
9. In the minds eye: How the brain makes a whole out of parts
10. African parasite makes component of fat differently from all other organisms
11. Coffee makes us more likely to say yes

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/20/2017)... , March 20, 2017 At this year,s ... -based biometrics manufacturer DERMALOG. The Chancellor came to the DERMALOG stand ... is this year,s CeBIT partner country. At the largest German biometrics ... in use: fingerprint, face and iris recognition as well as DERMALOG´s multi-biometrics ... ...
(Date:3/9/2017)... Australia , March 9, 2017 ... the prestigious World Lung Imaging Workshop at the University ... , was invited to deliver the latest data to ... globally recognised event brings together leaders at the forefront ... developments in lung imaging. "The quality ...
(Date:3/6/2017)... 2017 Mintigo , the leader ... Predictive Sales Coach TM , its new artificial ... into Salesforce. This unique AI application will allow ... with deep knowledge of their customers and prospects ... Predictive Sales Coach extends Mintigo,s existing customer success ...
Breaking Biology News(10 mins):
(Date:3/28/2017)... ... March 28, 2017 , ... ... Marketing Roundtable on March 22 in Philadelphia. The event was offered by the ... Marketing Roundtable featured breakout groups and interaction with speakers who are ...
(Date:3/28/2017)... ... March 28, 2017 , ... Triumph Modular Incorporated, ... Institute (MBI), an international modular trade organization, were awarded First Place, as well ... Pagliuca Life Lab at Harvard University. The awards were presented at the 34th ...
(Date:3/28/2017)... WASHINGTON , March 28, 2017  (AACR17, ... single-cell sequencing during the American Association for Cancer Research ... Center in Washington, D.C. , April ... gene expression of thousands of cells at the individual ... Experts on-hand at AACR to discuss expanded ...
(Date:3/28/2017)... -- The National Pharmaceutical Council (NPC) today announced that Ipsen ... as its newest member. David Cox , PhD, ... America ), will serve as his company,s representative ... to have Ipsen and Dr. Cox join NPC as ... welcome their insights in helping us identify and address ...
Breaking Biology Technology: