학술논문

Differential galanin upregulation in dorsal root ganglia and spinal cord after graded single ligature nerve constriction of the rat sciatic nerve
Document Type
Report
Source
Journal of Chemical Neuroanatomy. Jan, 2008, Vol. 35 Issue 1, p94, 7 p.
Subject
Tyrosine
Neuropeptide Y
Neurons
Neurosciences
Language
English
ISSN
0891-0618
Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jchemneu.2007.07.001 Byline: Maria Florencia Coronel (a), Pablo Rodolfo Brumovsky (a)(b), Tomas Hokfelt (c), Marcelo Jose Villar (a) Keywords: Neuropeptides; Neuropathic pain; Peripheral nervous system; Primary afferent neurons; Immunohistochemistry Abstract: Single ligature nerve constriction (SLNC) is a newly developed animal model for the study of neuropathic pain. SLNC of the rat sciatic nerve induces pain-related behaviors, as well as changes in the expression of neuropeptide tyrosine and the Y.sub.1 receptor in lumbar dorsal root ganglia (DRGs) and spinal cord. In the present study, we have analyzed the expression of another neuropeptide, galanin, in lumbar DRGs and spinal cord after different degrees of constriction of the rat sciatic nerve. The nerve was ligated and reduced to 10-30, 40-80 or 90% of its original diameter (light, medium or strong SLNCs). At different times after injury (7, 14, 30, 60 days), lumbar 4 and 5 DRGs and the corresponding levels of the spinal cord were dissected out and processed for galanin-immunohistochemistry. In DRGs, SLNC induced a gradual increase in the number of galanin-immunoreactive (IR) neurons, in direct correlation with the degree of constriction. Thus, after light SLNC, a modest upregulation of galanin was observed, mainly in small-sized neurons. However, following medium or strong SLNCs, there was a more drastic increase in the number of galanin-IR neurons, involving also medium and large-sized cells. The highest numbers of galanin-IR neurons were detected 14 days after injury. In the dorsal horn of the spinal cord, medium and strong SLNCs induced a marked ipsilateral increase in galanin-like immunoreactivity in laminae I-II. These results show that galanin expression in DRGs and spinal cord is differentially regulated by different degrees of nerve constriction and further support its modulatory role on neuropathic pain. Author Affiliation: (a) School of Biomedical Sciences, Austral University, Av. Pte. Peron 1500, B1629AHJ Pilar, Buenos Aires, Argentina (b) Department of Anesthesiology, University of Pittsburgh, 200 Lothrop Street, W1402 BST Pittsburgh, PA 15213-2536, USA (c) Department of Neuroscience, Karolinska Institutet, Retzius Vag 8, S-171 77 Stockholm, Sweden Article History: Received 11 May 2007; Revised 11 July 2007; Accepted 14 July 2007