Bienvenido al ::: SerTox :::!

· Noticias
· Institucional
· Investigación
· Materiales Educativos
· Biblioteca multimedia
· Preguntas frecuentes
· Boletín
· Buscar
· Contáctenos
· Enlaces - Directorio
· Glosario
· Noticias x Mes
· Temas
· Top 15



· Todas las Categorías
· Aportes
· Ejercicios
· Informan / Escriben
· La prensa
· Noticias del Sertox
· Recomendamos
· Toxicología al día
· Trivia toxicológica
· zNo sólo de tóxicos


     Manifiesto amianto

 Toxicología al día: How opioids create a feeling of pleasure, study

Ver Imagen

Medicamento recetado (Foto: Sertox )

Prescription Drug Abuse Explained: Painkiller Addiction May Stem From How Opiates Affect Brain’s Reward System. By Susan Scutti.  February 24, 2014. Worldwide, an estimated 12 to 21 million people abuse opioids — including prescription pain killers, morphine, and heroin — while in the U.S. alone, 1.9 million people are addicted to prescription pain relievers.  Although the seduction of opioids may be clear to some people, what remains unknown is the effect of these drugs on specific pathways in the brain. Now, research led by a scientist at the Icahn School of Medicine at Mount Sinai reveals that use of opiates alters the activity of a specific protein known as RGS9-2, which in turn impacts and alters the normal functioning of the brain's reward center. By identifying the specific brain pathways that promote pain relief, addiction, and tolerance, the researchers are hoping to develop less dangerous yet more effective analgesics.

How Opiates Create a Feeling of Pleasure

What exactly happens in your body when you take an opiate such as the painkiller oxycodone? Essentially, after swallowing the pill, the chemicals travel through your bloodstream all the way to your brain, where they link up and attach themselves to specialized proteins known as mu opioid receptors. Once this chemical connection occurs, it sends a signal to the ventral tegmental area in the midbrain, which is involved in cognition, motivation, and most importantly reward, and from there, the brain dumps a neurotransmitter, dopamine, into the nucleus accumbens. This entire biochemical process — this pathway through the brain's biochemical circuitry — and in particular the release of dopamine, which has been linked to every type of reward that has ever been studied, creates a feeling of pleasure, even euphoria. Indeed, this very same series of reactions occur whenever you eat or orgasm.

For some time, scientists have understood the big picture of what happens in the brain when a person takes an opiate. What scientists are trying to discover now is the biochemical progress that takes place at the smallest, molecular level.

For the current study, senior researcher Dr. Venetia Zachariou, associate professor in the Department of Pharmacology and Systems Therapeutics at the Icahn School of Medicine at Mount Sinai, designed an experiment using mice. She and her colleagues employed optogenetics, a new technique that allows scientists to activate specific neurons to determine the exact cell types of the brain reward center responsible for the reduced analgesic response. Past research conducted by Zachariou suggested RGS9-2, a signaling protein, may terminate the activity of opioid receptors in the brain, and this process may be linked to the development of tolerance — in short, this may be key to why some people become addicted to opioids and others do not. To better understand the role played by RGS9-2, then, Zachariou and her colleagues alternately blocked the protein and increased its expression in a mouse’s nucleus accumbens, one component of the brain's reward center.

What did the researchers discover? The actions of opioids altered dramatically with each manipulation of the RGS9-2. "In our earlier work, by inactivating RGS9-2, we saw a tenfold increase in sensitivity to the rewarding actions of morphine, severe morphine dependence, a better analgesic response, and delayed development of tolerance," Zachariou stated in a press release. "We were able to block addiction-related behaviors, but increasing the activity of the protein also lowered the pain relief response to morphine, and mice developed morphine tolerance much more quickly."

Zachariou explained that the brain's reward center has a strong impact on analgesic responses, and it is for this reason non-opioid medications need to be developed. By targeting the RGS9-2 protein, scientists might someday develop an alternative therapy that offers relief without addiction for patients who suffer chronic conditions that cause pain.


Source: Zachariou V, Lobo MK, Deisseroth K, et al.  Nucleus Accumbens Specific Interventions in RGS9-2 Activity Modulate Responses to Morphine. Neuropsychopharmacology. 2014.

Enviado por jcp el 24 febrero 2014 00:00:00 (721 Lecturas)

Artículos e imágenes de:
 Artículos y Textos Científicos
Artículos y Textos Científicos
 Drogas: Opioides
Drogas: Opioides
 País: Estados Unidos y Canadá
País: Estados Unidos y Canadá

     Enlaces Relacionados

Noticia más leída sobre Artículos y Textos Científicos:
De Martín Cañás: Herbalife + hepatotoxicidad

     Votos del Artículo
Puntuación Promedio: 0
votos: 0

Por favor tómate un segundo y vota por este artículo:

Muy Bueno


Todos los logos y marcas registradas son propiedad de sus respectivos dueños. Los comentarios son propiedad de quienes lo envían, todo el resto © 2006-2011 by Sertox.

Webs Asociadas: / Radio FM Estacion San Pedro / Lombó Teatro Salamanca - Zamora

PHP-Nuke Copyright © 2005 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.
Página Generada en: 0.05 Segundos