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The pattern of Fos expression in the spinal dorsal horn following acute noxious mechanical stimulation of bone
Author(s) -
Ivanusic Jason J.
Publication year - 2008
Publication title -
european journal of pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.305
H-Index - 109
eISSN - 1532-2149
pISSN - 1090-3801
DOI - 10.1016/j.ejpain.2007.12.017
Subject(s) - spinal cord , nociception , french horn , anatomy , noxious stimulus , stimulation , medicine , endocrinology , psychology , receptor , pedagogy , psychiatry
Little is known of the spinal mechanisms that mediate bone nociception. The aim of this study was to determine the pattern of neuronal activation in the spinal dorsal horn following acute noxious mechanical stimulation of bone. This was achieved by examining Fos expression in the spinal dorsal horn following acute, noxious mechanical stimulation of the rat tibia. Noxious mechanical stimuli were applied by bone drilling and raising tibial intra‐osseous pressure. Control experiments consisted of surgery to expose the tibia. There was a significant increase in the number of Fos‐like immunoreactive (Fos‐LI) nuclei in the superficial, ipsilateral dorsal horn of animals in the bone drilling and pressure groups relative to animals of the control group at spinal cord segments L3 and L4 ( P <0.05). The number of Fos‐LI nuclei in the deep dorsal horn was always lower than the number in the superficial dorsal horn (significant at L3 but not L4; P <0.05). Whilst there appeared to be a small increase in the number of Fos‐LI nuclei in the ipsilateral deep dorsal horn of bone drilling and pressure groups relative to the ipsilateral deep dorsal horn control group at both L3 and L4 segments, no significant effect was observed ( P >0.05). The present study implicates the superficial dorsal horn of the spinal cord as a region of interest in studies of acute bone pain, and highlights the notion that spinal mechanisms that mediate bone nociception may be different to those that mediate nociception of cutaneous and visceral origin.