| Las neuronas noradrenérgicas en el núcleo ceruleus contribuyen al dolor neuropático |
Noradrenergic neurons in the locus coeruleus contribute to neuropathic pain.
Brightwell JJ, Taylor BK.
Department of Pharmacology, School of Medicine, Tulane University, New Orleans, LA 70112, USA.
Neuroscience. 2009 Apr 21;160(1):174-85. doi: 10.1016/j.neuroscience.2009.02.023. Epub 2009 Feb 14.
Abstract
Current theories of neuropathic hypersensitivity include an imbalance of supraspinal inhibition and facilitation. Our overall hypothesis is that the locus coeruleus (LC), classically interpreted as a source of pain inhibition, may paradoxically result in facilitation after tibial and common peroneal nerve transection (spared sural nerve injury--SNI). We first tested the hypothesis that non-noxious tactile hind paw stimulation of the spared sural innervation territory increases neuronal activity in the LC in male rats. We observed a bilateral increase in the stimulus-evoked expression of transcription factors Fos and phosphorylated CREB (pCREB) in LC after SNI but not sham surgery; these markers of neuronal activity correlated with the intensity of tactile allodynia. We next tested the hypothesis that noradrenergic neurons contribute to the development of neuropathic pain. To selectively destroy these neurons, we delivered antidopamine-beta-hydroxylase saporin (anti-DbetaH-saporin) into the i.c.v. space 2 weeks before SNI. We found that anti-DbetaH-saporin, but not an IgG-saporin control, reduced behavioral signs of tactile allodynia, mechanical hyperalgesia, and cold allodynia from 3 to 28 days. after SNI. Our final experiment tested the hypothesis that the LC contributes to the maintenance of neuropathic pain. We performed SNI, waited 2 weeks for maximal allodynia and hyperalgesia to develop, and then administered the local anesthetic lidocaine (4%) directly into the LC parenchyma. Lidocaine reduced all behavioral signs of neuropathic pain in a reversible manner, suggesting that the LC contributes to pain facilitation. We conclude that, in addition to its well-known inhibition of acute and inflammatory pain, the LC facilitates the development and maintenance of neuropathic pain in the SNI model. Further studies are needed to determine the facilitatory pathways emanating from the LC.
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| Plasticidad molecular y celular inducida por opioides en las neuronas catecolaminérgicas del área tegmentaria ventral y el locus ceruleus |
Opiate-induced molecular and cellular plasticity of ventral tegmental area and locus coeruleus catecholamine neurons.
Mazei-Robison MS, Nestler EJ.
Fishberg Department of Neuroscience and Friedman Brain Institute, Mount Sinai School of Medicine, New York, New York, USA.
Cold Spring Harb Perspect Med. 2012 Jul;2(7):a012070
. doi: 10.1101/cshperspect.a012070.
Abstract
The study of neuronal adaptations induced by opiate drugs is particularly relevant today given their widespread prescription and nonprescription use. Although much is known about the acute actions of such drugs on the nervous system, a great deal of work remains to fully understand their chronic effects. Here, we focus on longer-lasting adaptations that occur in two catecholaminergic brain regions that mediate distinct behavioral actions of opiates: ventral tegmental area (VTA) dopaminergic neurons, important for drug reward, and locus coeruleus (LC) noradrenergic neurons, important for physical dependence and withdrawal. We focus on changes in cellular, synaptic, and structural plasticity in these brain regions that contribute to opiate dependence and addiction. Understanding the molecular determinants of this opiate-induced plasticity will be critical for the development of better treatments for opiate addiction and perhaps safer opiate drugs for medicinal use.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3385942/pdf/cshperspectmed-ADD-a012070.pdf
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| Núcleo Coeruleus. Neurotransmisores, Funciones y Patología. |
Dr. Mauricio Valenzuela-Harrington, Dr. Vicente Negrete-Díaz, Dr. Antonio Rodríguez-Moreno
Anestesia en México 2007;19:155-166.
El Nucleus Coeruleus es la principal fuente de noradrenalina en el sistema nervioso central. Este complejo nuclear debido a sus aferencias y eferencias está involucrado en diversas y variadas funciones. Además está involucrado en diversas enfermedades y alteraciones del sistema nervioso central cuando su funcionamiento no es correcto. En esta revisión se describen estas funciones del nucleus coeruleus así como la forma en que participa en enfermedades del sistema nervioso tales como Enfermedad de Alzheimer, Parkinson, Depresión y estrés y su papel en procesos de drogodependencia y síndrome de abstinencia.
Palabras claves: Locus Coeruleus, noradrenalina, neuromodulador, receptores a y b adrenérgicos.
http://www.anestesiaenmexico.org/RAM9/RAM2007-19-3/007.pdf
Atentamente
Anestesiología y Medicina del Dolor
www.anestesia-dolor.org
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