Navigation Links
Key Trigger Of Opioid Withdrawal Symptoms Found

Researchers have discovered an important chemical in the brain's neuronal machinery that triggers some of the withdrawal symptoms of opioid drugs like morphine and heroin.

They believe that drugs to inhibit the chemical--called a transporter--could relieve some of the early physical symptoms of withdrawal, such as teeth-chattering, uncontrolled shaking, and jumpiness. Such drugs could become part of the arsenal of medicines and behavioral techniques aimed at helping addicts kick their habits.


To zero in on the machinery underlying withdrawal symptoms, researchers led by Elena Bagley and Macdonald Christie of the Pain Management Research Institute at Royal North Shore Hospital (a division of the University of Sydney) performed biochemical studies on brain slices from mice that had been treated with morphine. Their objective was to understand what happens to a particular region of the midbrain--called the periaqueductal gray (PAG)--known to be involved in such withdrawal symptoms. Opiate addiction inhibits neuron activity in this region, which alters the neuronal machinery to compensate for this inhibition. Upon opiate withdrawal, the neurons rebound, becoming hyperactive.

The scientists' analysis revealed that a transporter molecule for the neurotransmitter GABA was responsible for the electrical abnormalities that produce a hyperexcitability in the neurons. Neurotransmitters are the molecular ammunition that one neuron fires at its neighbor to trigger a nerve impulse in the neighbor. Propagation of such nerve impulses through the networks of neurons in the brain is the basis of all neural activity. Transporter molecules are the proteins that retrieve neurotransmitter molecules from the spaces between neurons after they trigger nerve impulse, to reload the neuron for its next signaling burst.

Bagley and her colleagues also discovered that a molecular switch called protein kinase A was part of the triggering machinery involved in activating the abnormal GABA transporter activity.

Importantly, the researchers found that drugs that inhibit either the GABA transporter activity or protein kinase A eliminate the hyperexcitability of the PAG neurons in the mouse brain slices.

The researchers cited other studies showing that treatment with opioids also altered levels of the transporter for the neurotransmitter glutamate, "suggesting that neurotransmitter transporters may prove to be useful targets for management of opioid dependence," they wrote. The researchers also wrote that, since GABA is a neurotransmitter that inhibits nerve impulses, drugs to inhibit the GABA transporter "could produce their therapeutic effect through altering extracellular GABA concentrations as well as directly altering the excitability of GABAergic neurons."

###

Elena E. Bagley, Michelle B. Gerke, Christopher W. Vaughan, Stephen P. Hack, and MacDonald J. Christie: "GABA Transporter Currents Activated by Protein Kinase A Excite Midbrain Neurons during Opioid Withdrawal"

Publishing in Neuron, Volume 45, Number 3, February 3, 2005, pages 433?45. http://www.neuron.org


'"/>

Source:Cell Press


Related biology news :

1. Bacteria in Household Dust May Trigger Asthma Symptoms
2. Opiates Better Than Sedatives For Treating Newborns In Withdrawal
3. Menopause Symptoms May Come Back After Stopping Menopausal Hormone Therapy
4. Synthetic Protein Eases Arthritis Symptoms in Mice
5. Potential Drug Target For Treating Cocaine Abuse Found
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/11/2017)... GARDENS, Fla. , April 11, 2017 /PRNewswire/ ... management and secure authentication solutions, today announced that ... by Intelligence Advanced Research Projects Activity (IARPA) to ... IARPA,s Thor program. "Innovation has been ... and IARPA,s Thor program will allow us to ...
(Date:4/11/2017)... MELBOURNE, Florida , April 11, 2017 ... "Company"), a security technology company, announces the appointment of independent ... John Bendheim to its Board of Directors, furthering the ... ... behalf of NXT-ID, we look forward to their guidance and ...
(Date:4/5/2017)... NEW YORK , April 5, 2017 ... security, is announcing that the server component of the ... is known for providing the end-to-end security architecture that ... customers. HYPR has already secured over 15 ... system makers including manufacturers of connected home product suites ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... publication of a United States multicenter, prospective clinical study that demonstrates the ... diagnostic test capable of identifying clinically significant acute bacterial and viral respiratory ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... the first-ever genomics analysis platform specifically designed for life science researchers to ... of pioneering researcher Rosalind Franklin, who made a major contribution to the ...
(Date:10/11/2017)... ... October 11, 2017 , ... Personal eye wash is a basic first aid supply for ... time. So which eye do you rinse first if a dangerous substance enters both eyes? ... Eye Wash with its unique dual eye piece. , “Whether its dirt and debris, ...
(Date:10/11/2017)...  VMS BioMarketing, a leading provider of patient support solutions, ... Educator (CNE) network, which will launch this week. The VMS ... care professionals to enhance the patient care experience by delivering ... health care professionals to help women who have been diagnosed ... ...
Breaking Biology Technology: