c-Fos expression in rat spinal cord induced by scorpion BmK venom via plantar subcutaneous injection.
The aim of this study was to assess the cell-type and distribution of highly activated neurons in rat spinal cord underlying nociceptive responses induced by scorpion BmK venom using Fos immunohistochemistry. BmK venom was intraplantarly injected into one hind paw of a conscious rat. Fos-like immunoreactive neurons were found to predominantly distribute at L4-5 segments in the rat spinal cord after BmK venom application. c-Fos labeling was most dense in the medial half portion of laminae I-II, moderately dense in laminae V-VI and less dense in laminae III-IV, VII-X. c-Fos labeling could be detected at 0.5 h, reached the peak at 2 h, decreased steeply from 4 h and then almost disappeared at 24 h. Ten to fifty micrograms of BmK venom was deemed to be a sufficient dosage to evoke c-Fos expression. On the other hand, c-Fos expression induced by BmK venom could be suppressed partially by systemic morphine in a dose-dependent manner. The results suggest that the different extent of activities of neuronal subpopulation in the spinal cord involved in nociceptive transmission manifesting as c-Fos expression, were mainly correlated with mechanisms underlying the generation, maintenance and/or modulation of spontaneous pain and hyperalgesia evoked by BmK venom.
Bai
Zhan-Tao
ZT
Department of Biology of Yanan University, Yanan 716000, People's Republic of China.
Chen
Bing
B
Zhang
Xu-Ying
XY
Fan
Guang-Li
GL
Ji
Yong-Hua
YH
D000344:Afferent Pathways / Q000187:drug effects* / Q000502:physiology; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007150:Immunohistochemistry; D007279:Injections, Subcutaneous; D008159:Lumbar Vertebrae; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects* / Q000502:physiology; D010146:Pain / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology; D020671:Posterior Horn Cells / Q000187:drug effects* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012604:Scorpion Venoms / Q000037:antagonists & inhibitors*; D012867:Skin / Q000187:drug effects / Q000294:innervation; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D000701:Analgesics, Opioid; D016760:Proto-Oncogene Proteins c-fos; D012604:Scorpion Venoms; C105338:makatoxin I; D009020:Morphine