Permanent lesion in rostral ventromedial medulla potentiates swim stress-induced analgesia in formalin test

Document Type: Original Article


1 Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran

2 Department of Physiology & Pharmacology, Cellular and Molecular Research Center, Sabzevar University of Medical Sciences, Sabzevar, Iran

3 Department of Basic Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran


Objective(s): There are many reports about the role of rostral ventromedial medulla (RVM) in modulating stress-induced analgesia (SIA). In the previous study we demonstrated that temporal inactivation of RVM by lidocaine potentiated stress-induced analgesia. In this study, we investigated the effect of permanent lesion of the RVM on SIA by using formalin test as a model of acute inflammatory pain.
Materials and Methods: Three sets of experiments were conducted: (1) Application of stress protocol (2) Formalin injection after exposing the animals to the swim stress (3) Either the relevant vehicle or dopamine receptor 1 (D1) agonist R-SKF38393 was injected into the RVM to cause a lesion. For permanent lesion of RVM, R-SKF38393 was injected into the RVM. Forced swim stress in water was employed in adult male rats. Nociceptive responses were measured by formalin test (50µl injection of formalin 2% subcutaneously into hind paw) and pain related behaviors were monitored for 90 min.
Results: In the unstressed rats, permanent lesion of the RVM by R-SKF38393 decreased formalin-induced nociceptive behaviors in phase 1, while in stressed rats, injection of R-SKF38393 into the RVM potentiated swim stress-induced antinociception in phase 1 and interphase, phase 2A of formalin test. Furthermore, R-SKF38393 had pronociceptive effects in phase2B whereas injections of R-SKF38393 resulted in significant difference in nociceptive bahaviours in all phases of formalin test (P<0.05).
Conclusion: The result of the present study demonstrated that permanent inactivation of RVM can potentiate stress-induced analgesia in formalin test.


 1. Butler RK, Finn DP. Stress-induced analgesia. Prog Neurobiol 2009;88:184-202.

2. Bodnar RJ, Kelly DD, Brutus M, Glusman M. Stress-induced analgesia: neural and hormonal determinants. Neurosci Biobehav Rev 1980;4:87-100. RVM inactivation potentiates stress-induced analgesia Shamsizadeh et al

 3. Guillemin R, Vargo T, Rossier J, Minick S, Ling N, Rivier C,et al. beta-Endorphin and adrenocortico-tropin are selected concomitantly by the pituitary gland. Sci 1977; 197:1367-1369.

4. Madden Jt, Akil H, Patrick RL, Barchas JD. Stress-induced parallel changes in central opioid levels and pain responsiveness in the rat. Nature 1977;265:358-360.

5. Park CH, Hitri A, Lukacs LG, Deutsch SI. Swim stress selectively alters the specific binding of a benzodiazepine antagonist in mice. Pharmacol Biochem Behav 1993;45:299-304.

6. Vaswani KK, Richard CW, 3rd, Tejwani GA. Cold swim stress-induced changes in the levels of opioid peptides in the rat CNS and peripheral tissues. Pharmacol Biochem Behav 1988;29:163-168.

7. Lewis JW, Cannon JT, Liebeskind JC. Opioid and nonopioid mechanisms of stress analgesia. Science 1980;208:623-625.

8. Watkins LR, Mayer DJ. Organization of endogenous opiate and nonopiate pain control systems. Science 1982;216:1185-1192.

9. Amit Z, Galina ZH. Stress-induced analgesia: adaptive pain suppression. Physiol Rev 1986;66:1091-1120.

10. Watkins LR, Mayer DJ. Multiple endogenous opiate and non-opiate analgesia systems: evidence of their existence and clinical implications. Ann N Y Acad Sci 1986;467:273-299.

11. Mayer DJ, Price DD. Central nervous system mechanisms of analgesia. Pain 1976;2:379-404.

12. Millan MJ. Descending control of pain. Prog Neurobiol 2002;66:355-474.

13. 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;6:427-439.

14. Ambriz-Tututi M, Cruz SL, Urquiza-Marin H, Granados-Soto V. Formalin-induced long-term secondary allodynia and hyperalgesia are maintained by descending facilitation. Pharmacol Biochem Behav 2011;98:417-424.

15. Kim SJ, Calejesan AA, Zhuo M. Activation of brainstem metabotropic glutamate receptors inhibits spinal nociception in adult rats. Pharmacol Biochem Behav 2002;73:429-437.

16. Heinricher MM and Ingram sL The Brainstem and. Nocieceptive Modulation.Vancouver: WA, USA, 2007.

17. Martindale J, Bland-Ward PA, Chessell IP. Inhibition of C-fibre mediated sensory transmission in the rat following intraplantar formalin. Neurosci Lett 2001;316:33-36.

18. Tjolsen A, Berge OG, Hunskaar S, Rosland JH, Hole K. The formalin test: an evaluation of the method. Pain 1992;51:5-17.

19. Coderre TJ, Vaccarino AL, Melzack R. Central nervous system plasticity in the tonic pain response to subcutaneous formalin injection. Brain Res 1990;535:155-158.

20. Wiedenmayer CP, Goodwin GA, Barr GA. The effect of periaqueductal gray lesions on responses to age-specific threats in infant rats. Brain Res Dev Brain Res 2000;120:191-198.

21. Morgan MM, Whittier KL, Hegarty DM, Aicher SA. Periaqueductal gray neurons project to spinally projecting GABAergic neurons in the rostral ventromedial medulla. Pain 2008;140:376-386.

22. Azhdari-Zarmehri Hassan, Heidari-Oranjaghi N, Soleimani N, Sofi-Abadi M. Effects of lidocaine injections into the rostral ventromedial medulla on nociceptive behviours in hot-plate and formalin tests in rats. Koomesh 2013;14(4):490-496.

23. Soleimani N, Erami E, Abbasnejad M, sh, Azhdari-Zarmehri Hassan. Effect of transient inactivation of rostral ventromedial medulla on swim stress induced analgesia in formalin test in rats. Physiol-Pharmacol 2013;17(1):116-124.

24. Vanderah TW, Suenaga NM, Ossipov MH, Malan TP Jr, Lai J, Porreca F. Tonic descending facilitation from the rostral ventromedial medulla mediates opioid-induced abnormal pain and antinociceptive tolerance. J Neurosci 2001; 21:279-286.

25. Paxinos,G, Watson,C. The rat brain in stereotaxic coordinates. New York: Academic Press. 2005.

26. Azhdari Zarmehri H, Semnanian S, Fathollahi Y, Erami E, Khakpay R, Azizi H,et al. Intra-periaqueductal gray matter microinjection of orexin-A decreases formalin-induced nociceptive behaviors in adult male rats. J Pain 2011;12:280-287.

27. Fereidoni M, Javan M, Semnanian S, Ahmadiani A. Chronic forced swim stress inhibits ultra-low dose morphine-induced hyperalgesia in rats. Behav Pharmacol 2007;18:667-672.

28. Quintero L, Cuesta MC, Silva JA, Arcaya JL, Pinerua-Suhaibar L, Maixner W,et al. Repeated swim stress increases pain-induced expression of c-Fos in the rat lumbar cord. Brain Res 2003;965:259-268.

29. Heidari-Oranjaghi N, Azhdari-Zarmehri H, Erami E, Haghparast A. Antagonism of orexin-1 receptors attenuates swim- and restraint stress-induced antinociceptive behaviors in formalin test. Pharmacol Biochem Behav 2012;103:299-307.

30. Moore PA, Hersh EV, Papas AS, Goodson JM, Yagiela JA, Rutherford B,et al. Pharmacokinetics of lidocaine with epinephrine following local anesthesia reversal with phentolamine mesylate. Anesth Prog 2008;55:40-48.

31. Azhdari-Zarmehri Hassan, Rahmani A, Puzesh S, Erami E, Emamjomeh MM. Assessing the Effect of Lidocaine Injection into the Nucleus Paragigantocellularislateralis on Formalin Test and Hot Plate Test Induced Nociceptive Behaviors in Rats. ZUMS Journal 2013;21(85):10-29.

32. Kelley AE, Delfs JM, Chu B. Neurotoxicity induced by the D-1 agonist SKF 38393 following microinjection into rat brain. Brain Res 1990;532:342-346.

33. Gorelova NA, Yang CR. Dopamine D1/D5 receptor activation modulates a persistent sodium current in rat prefrontal cortical neurons in vitro. J Neurophysiol2000;84:75-87.

34. Isaac L, Mills R, Fowler LJ, Starr BS, Starr MS. Putative neurotoxicity of SKF 38393 and other D1 dopaminergic drugs investigated in rat striatum. J Neurochem 1992;58:1464-1468.

35. Manning BH. A lateralized deficit in morphine antinociception after unilateral inactivation of the central amygdala. J Neurosci 1998;18:9453-9470.Shamsizadeh et al RVM inactivation potentiates stress-induced analgesia

36. Urban MO, Gebhart GF. Supraspinal contributions to hyperalgesia. Proc Natl Acad Sci USA 1999; 96:7687-7692.

37. Heinricher MM, Neubert MJ. Neural basis for the hyperalgesic action of cholecystokinin in the rostral ventromedial medulla. J Neurophysiol. 2004; 92(4): 1982-9.

38. Azhdari-Zarmehri H, Semnanian S, Fathollahi Y, Pakdell FG. Tail flick modification of orexin-A-induced changes of electrophysiological parameters in the rostral ventromedial medulla. Cell J (Yakhteh) 2014;16(2).

39. Bederson JB, Fields HL, Barbaro NM. Hyperalgesia during naloxone-precipitated withdrawal from morphine is associated with increased on-cell activity in the rostral ventromedial medulla. Somatosens Mot Res 1990;7:185-203.

40. Heinricher MM, Morgan MM, Fields HL. Direct and indirect actions of morphine on medullary neurons that modulate nociception. Neuroscience 1992;48:533-543.

41. Barbaro NM, Heinricher MM, Fields HL. Putative pain modulating neurons in the rostral ventral medulla: reflex-related activity predicts effects of morphine. Brain Res 1986;366:203-210.

42. Fields HL, Heinricher MM. Anatomy and physiology of a nociceptive modulatory system. Philos Trans R Soc Lond B Biol Sci 1985;308:361- 374.

43. Foo H, Helmstetter FJ. Hypoalgesia elicited by a conditioned stimulus is blocked by a mu, but not a delta or a kappa, opioid antagonist injected into the rostral ventromedial medulla. Pain 1999;83:427-431.

44. Helmstetter FJ, Tershner SA. Lesions of the periaqueductal gray and rostral ventromedial medulla disrupt antinociceptive but not cardiovascular aversive conditional responses. J Neurosci 1994;14:7099-7108.

45. Imbe H, Murakami S, Okamoto K, Iwai-Liao Y, Senba E. The effects of acute and chronic restraint stress on activation of ERK in the rostral ventromedial medulla and locus coeruleus. Pain 2004;112:361-371.

46. Rivat C, Becker C, Blugeot A, Zeau B, Mauborgne A, Pohl M,et al. Chronic stress induces transient spinal neuroinflammation, triggering sensory hypersensitivity and long-lasting anxiety-induced hyperalgesia. Pain 2010;150:358-368.

47. Cornelio AM, Nunes-de-Souza RL, Morgan MM. Contribution of the rostral ventromedial medulla to post-anxiety induced hyperalgesia. Brain Res 2012;1450:1480-6.

48. Morgan MM, Whitney PK. Immobility accompanies the antinociception mediated by the rostral ventromedial medulla of the rat. Brain Res 2000;872:276-281.

49. Watkins LR, Young EG, Kinscheck IB, Mayer DJ. The neural basis of footshock analgesia: the role of specific ventral medullary nuclei. Brain Res 1983;276:305-315.

50. Coderre TJ, Yashpal K. Intracellular messengers contributing to persistent nociception and hyperalgesia induced by L-glutamate and substance P in the rat formalin pain model. Eur J Neurosci 1994;6:1328-1334.

51. Hopkins E, Spinella M, Pavlovic ZW, Bodnar RJ. Alterations in swim stress-induced analgesia and hypothermia following serotonergic or NMDA antagonists in the rostral ventromedial medulla of rats. Physiol Behav 1998;64:219-225.

52. Leitner DS, Kelly DD. Potentiation of cold swim stress analgesia in rats by diazepam. Pharmacol Biochem Behav 1984;21:813-116.

53. Spinella M, Bodnar RJ. Nitric oxide synthase inhibition selectively potentiates swim stress antinociception in rats. Pharmacol Biochem Behav 1994;47:727-733.

54. Heinricher MM, Martenson ME, Nalwalk JW, Hough LB. Neural basis for improgan antinociception. Neuroscience 2010;169:1414-1420.

55. Mitchell JM, Lowe D, Fields HL. The contribution of the rostral ventromedial medulla to the antinociceptive effects of systemic morphine in restrained and unrestrained rats. Neuroscience 1998;87:123-133.

56. Burgess SE, Gardell LR, Ossipov MH, Malan TP Jr, Vanderah TW, Lai J,et al. Time-dependent descending facilitation from the rostral ventromedial medulla maintains, but does not initiate, neuropathic pain. J Neurosci 2002;22:5129-5136.

57. Kincaid W, Neubert MJ, Xu M, Kim CJ, Heinricher MM. Role for medullary pain facilitating neurons in secondary thermal hyperalgesia. J Neurophysiol 2006;95:33-41.

58. Neubert MJ, Kincaid W, Heinricher MM. Nociceptive facilitating neurons in the rostral ventromedial medulla. Pain 2004;110:158-165.

59. Porreca F, Ossipov MH, Gebhart GF. Chronic pain and medullary descending facilitation. Trends Neurosci 2002;25:319-325.

60. de Novellis V, Mariani L, Palazzo E, Vita D, Marabese I, Scafuro M,et al. Periaqueductal grey CB1 cannabinoid and metabotropic glutamate subtype 5 receptors modulate changes in rostral ventromedial medulla neuronal activities induced by subcutaneous formalin in the rat. Neuroscience 2005;134:269-281.

61. 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;46:661-666.

62. Da Silva LF, Desantana JM, Sluka KA. Activation of NMDA receptors in the brainstem, rostral ventromedial medulla, and nucleus reticularis gigantocellularis mediates mechanical hyperalgesia produced by repeated intramuscular injections of acidic saline in rats. J Pain 2009;11:378-387.

63. Heinricher MM, Tortorici V. Interference with GABA transmission in the rostral ventromedial medulla: disinhibition of off-cells as a central mechanism in nociceptive modulation. Neuroscience 1994;63:533-546.

64. Sofi-Abadi M, Heidari-Oranjaghi N, Ghasemi E, Esmaeili MH, Haghdoost-Yazdi H, Erami E,et al. Assesment of orexin receptor 1 in stress attenuated nociceptive behaviours in formalin test. Physiology and Pharmacology [Article in Persian] 2011 ;12:188-93.