Decreased Formalin Induced Nociceptive Behaviors by Morphine Microinjection into the Nucleus Reticularis Paragigantocellularis Lateralis
DOI:
https://doi.org/10.22100/jkh.v6i2.114Keywords:
Morphine, Analgesic, Nucleus reticularis paragigantocellularis lateralis, Formalin testAbstract
Introduction: Systemic injections of morphine have been shown to elicit analgesic responses in formalin test. However, the locations of central sites that may mediate these effects have not been clearly elucidated. This study assessed the antinociceptive action of morphine after microinjection into the nucleus reticularis paragigantocellularis lateralis (LPGI) in the formalin test in rats. Formalin-induced behaviour is characterized by two phases relevant to acute and tonic.
Methods: In this behavioral study, Inflammatory Pain Model by formalin was used in white rats with weight range of 200-300g. Using a stereotaxic apparatus, canulla was inserted into the LPGI. After 1 week recovery, animals were initially submitted to the injection of 50 ml of 2% formalin solution in hind paw.
Results: Intra-LPGI microinjection of morphine produced robust inhibition of formalin-evoked behaviour in phase 1, interphase and phase 2 (P<0.001); however, exogenous injection of morphine in the LPGI had no effect on reducing formalin induced nociceptive behaviors
Conclusion: The results suggested that morphine plays an anti-nociceptive role in LPGI in phase 1, interphase and late phase of formalin test in rats, which suggests that opioid receptors in the LPGI may be involved in the LPGI -mediated depression of formalin test as inflammatory pain.
References
References
Andrezik JA, Chan-Palay V, Palay SL. The nucleus paragigantocellularis lateralis in the rat. Demonstration of afferents by the retrograde transport of horseradish peroxidase. Anat Embryol (Berl) 1981;161(4):373-90.
Andrezik JA, Chan-Palay V, Palay SL. The nucleus paragigantocellularis lateralis in the rat. Conformation and cytology. Anat Embryol (Berl) 1981;161(4):355-71.
Guyenet PG, Young BS. Projections of nucleus paragigantocellularis lateralis to locus coeruleus and other structures in rat. Brain Res 1987;406(1-2):171-84.
Shen F, Yu W. [Study of cytochemical properties in the nucleus paragigantocellularis lateralis of rats]. Hua Xi Yi Ke Da Xue Xue Bao 1994;25(3):271-4.
Lovick TA. Tonic GABAergic and cholinergic influences on pain control and cardiovascular control neurones in nucleus paragigantocellularis lateralis in the rat. Pain 1987;31(3):401-9.
Fields HL, Malick A, Burstein R. Dorsal horn projection targets of ON and OFF cells in the rostral ventromedial medulla. J Neurophysiol 1995;74(4):1742-59.
Heinricher MM, Barbaro NM, Fields HL. Putative nociceptive modulating neurons in the rostral ventromedial medulla of the rat: firing of on- and off-cells is related to nociceptive responsiveness. Somatosens Mot Res 1989;6(4):427-39.
Heinricher MM, McGaraughty S, Tortorici V. Circuitry underlying antiopioid actions of cholecystokinin within the rostral ventromedial medulla. J Neurophysiol 2001;85(1):280-6.
Dubuisson D, Dennis SG. The formalin test: a quantitative study of the analgesic effects of morphine, meperidine, and brain stem stimulation in rats and cats. Pain 1977;4(2):161-74.
G.Paxinos and C.Watson. The Rat Brain in Stereotaxic Coordinates (4th and 6th edition), Academic Press, New York (1998 and 2007). 2005.
Abbott FV, Franklin KB, Westbrook RF. The formalin test: scoring properties of the first and second phases of the pain response in rats. Pain 1995;60(1):91-102.
Basbaum AI, Clanton CH, Fields HL. Three bulbospinal pathways from the rostral medulla of the cat: an autoradiographic study of pain modulating systems. J Comp Neurol 1978;178(2):209-24.
Basbaum AI, Fields HL. The origin of descending pathways in the dorsolateral funiculus of the spinal cord of the cat and rat: further studies on the anatomy of pain modulation. J Comp Neurol 1979;187(3):513-31.
Oliveras JL, Redjemi F, Guilbaud G, Besson JM. Analgesia induced by electrical stimulation of the inferior centralis nucleus of the raphe in the cat. Pain 1975;1(2):139-45.
Oliveras JL, Hosobuchi Y, Redjemi F, Guilbaud G, Besson JM. Opiate antagonist, naloxone, strongly reduces analgesia induced by stimulation of a raphe nucleus (centralis inferior). Brain Res 1977;120(2):221-9.
Duggan AW, Griersmith BT. Inhibition of the spinal transmission of nociceptive information by supraspinal stimulation in the cat. Pain 1979;6(2):149-61.
Fields HL, Basbaum AI, Clanton CH, Anderson SD. Nucleus raphe magnus inhibition of spinal cord dorsal horn neurons. Brain Res 1977;126(3):441-53.
Proudfit HK, Anderson EG. Morphine analgesia: blockade by raphe magnus lesions. Brain Res 1975;98(3):612-8.
Dickenson AH, Oliveras JL, Besson JM. Role of the nucleus raphe magnus in opiate analgesia as studied by the microinjection technique in the rat. Brain Res 1979;170(1):95-111.
Levy RA, Proudfit HK. Analgesia produced by microinjection of baclofen and morphine at brain stem sites. Eur J Pharmacol 1979;57(1):43-55.
Akaike A, Shibata T, Satoh M, Takagi H. Analgesia induced by microinjection of morphine into, and electrical stimulation of, the nucleus reticularis paragigantocellularis of rat medulla oblongata. Neuropharmacology 1978;17(9):775-8.
Azami J, Llewelyn MB, Roberts MH. The contribution of nucleus reticularis paragigantocellularis and nucleus raphe magnus to the analgesia produced by systemically administered morphine, investigated with the microinjection technique. Pain 1982;12(3):229-46.
Franklin KB, Abbott FV. Pentobarbital, diazepam, and ethanol abolish the interphase diminution of pain in the formalin test: evidence for pain modulation by GABAA receptors. Pharmacol Biochem Behav 1993;46(3):661-6.
Stiller CO, Linderoth B, O'Connor WT, Franck J, Falkenberg T, Ungerstedt U, et al. Repeated spinal cord stimulation decreases the extracellular level of gamma-aminobutyric acid in the periaqueductal gray matter of freely moving rats. Brain Res 1995;699(2):231-41.
Silva E, Hernandez L, Contreras Q, Guerrero F, Alba G. Noxious stimulation increases glutamate and arginine in the periaqueductal gray matter in rats: a microdialysis study. Pain 2000;87(2):131-5.
Suh HW, Kim YH, Choi YS, Choi SR, Song DK. Effects of GABA receptor antagonists injected spinally on antinociception induced by opioids administered supraspinally in mice. Eur J Pharmacol 1996;307(2):141-7.
Maione S, Oliva P, Marabese I, Palazzo E, Rossi F, Berrino L, et al. Periaqueductal gray matter metabotropic glutamate receptors modulate formalin-induced nociception. Pain 2000;85(1-2):183-9.
Chaplan SR, Malmberg AB, Yaksh TL. Efficacy of spinal NMDA receptor antagonism in formalin hyperalgesia and nerve injury evoked allodynia in the rat. J Pharmacol Exp Ther 1997;280(2) 829-38.
Vaccarino AL, Clemmons HR, Mader GJ, Jr., Magnusson JE. A role of periaqueductal grey NMDA receptors in mediating formalin-induced pain in the rat. Neurosci Lett 1997;236(2):117-9.
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