Entanglement between thermoregulation and nociception in the rat: the case of morphine

Autor: Ivanne Pincedé, Daniel Le Bars, Nabil El Bitar, Elias Karroum, Bernard Pollin
Přispěvatelé: Physiopathologie des maladies psychiatriques = Pathophysiology of Psychiatric Disorders (NPS-07), Neurosciences Paris Seine (NPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Societe Francaise d'Etude et de Traitement de la Douleur (SFETD) et l'Institut UPSA de la douleur (IUD), Neuroscience Paris Seine (NPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2016
Předmět:
0301 basic medicine
Male
Nociception
Physiology
Narcotic Antagonists
Action Potentials
Blood Pressure
(+)-Naloxone
Rats
Sprague-Dawley
chemistry.chemical_compound
0302 clinical medicine
Heart Rate
rat
Neurons
thermoregulation
Medulla Oblongata
Morphine
Chemistry
Muscimol
Naloxone
General Neuroscience
Midbrain Raphe Nuclei
Thermoregulation
Analgesics
Opioid
Higher Neural Functions and Behavior
rostral medullary raphe
[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
medicine.symptom
rostral ventromedial medulla
medicine.drug
Body Temperature Regulation
Hyperthermia
medicine.medical_specialty
core temperature
Models
Biological
03 medical and health sciences
Internal medicine
medicine
Animals
GABA-A Receptor Agonists
medicine.disease
Rats
030104 developmental biology
Endocrinology
Vasoconstriction
Rostral ventromedial medulla
Skin Temperature
030217 neurology & neurosurgery
Zdroj: Journal of Neurophysiology
Journal of Neurophysiology, American Physiological Society, 2016, 116 (6), pp.2473-2496. ⟨10.1152/jn.00482.2016⟩
Journal of Neurophysiology, 2016, 116 (6), pp.2473-2496. ⟨10.1152/jn.00482.2016⟩
ISSN: 1522-1598
0022-3077
DOI: 10.1152/jn.00482.2016⟩
Popis: In thermoneutral conditions, rats display cyclic variations of the vasomotion of the tail and paws, the most widely used target organs in current acute or chronic animal models of pain. Systemic morphine elicits their vasoconstriction followed by hyperthermia in a naloxone-reversible and dose-dependent fashion. The dose-response curves were steep with ED50 in the 0.5–1 mg/kg range. Given the pivotal functional role of the rostral ventromedial medulla (RVM) in nociception and the rostral medullary raphe (rMR) in thermoregulation, two largely overlapping brain regions, the RVM/rMR was blocked by muscimol: it suppressed the effects of morphine. “On-” and “off-” neurons recorded in the RVM/rMR are activated and inhibited by thermal nociceptive stimuli, respectively. They are also implicated in regulating the cyclic variations of the vasomotion of the tail and paws seen in thermoneutral conditions. Morphine elicited abrupt inhibition and activation of the firing of on- and off-cells recorded in the RVM/rMR. By using a model that takes into account the power of the radiant heat source, initial skin temperature, core body temperature, and peripheral nerve conduction distance, one can argue that the morphine-induced increase of reaction time is mainly related to the morphine-induced vasoconstriction. This statement was confirmed by analyzing in psychophysical terms the tail-flick response to random variations of noxious radiant heat. Although the increase of a reaction time to radiant heat is generally interpreted in terms of analgesia, the present data question the validity of using such an approach to build a pain index.
Databáze: OpenAIRE
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