A contribution of neurokinin-1 receptor to formalin-induced c-fos expression in the rat spinal dorsal horn.
Formalin applied to a hindpaw of the rat resulted in c-fos expression in the spinal dorsal horn neurons on the ipsilateral side of stimulation. The role of neurokinin-1 (NK-1) receptor in this response was examined using a selective NK-1 antagonist L-668169. L-668169 administered intrathecally (1 microg/10 microl, 10 microg/10 microl) 15 min before injection of 2% formalin into one hindpaw significantly decreased the number of Fos-labeled neurons in the dorsal horn. A smaller dose of L-668169 (0.1 microg/10 microl) was ineffective. It was also showed that a selective NK-1 agonist Sar-SP perfused intrathecally (10 microg/10 microl) did result in the production of c-fos mainly in laminae I and that SP-like immunoreactive varicosities apposed neurons with Fos-labeled nuclei at their perikaryal membrane in the superficial laminae. These results indicate that NK-1 receptors may contribute to the activation of c-fos in the spinal dorsal horn neurons.
Tao
Y X
YX
Shanghai Brain Research Institute, Chinese Academy of Sciences, P.R. China.
Wei
F
F
Zhao
Z Q
ZQ
D000818:Animals; D000918:Antibody Specificity; D004594:Electrophysiology; D005557:Formaldehyde / Q000494:pharmacology*; D007150:Immunohistochemistry; D007278:Injections, Spinal; D008297:Male; D064729:Neurokinin-1 Receptor Antagonists; D010456:Peptides, Cyclic / Q000008:administration & dosage / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*
D064729:Neurokinin-1 Receptor Antagonists; D010456:Peptides, Cyclic; D016760:Proto-Oncogene Proteins c-fos; D018040:Receptors, Neurokinin-1; C076509:L 668169; D005557:Formaldehyde