NMDA receptors mediating Fos expression in rat spinal cord induced by subcutaneous injection of formalin.
OBJECTIVE
To examine the effects of N-methyl-D-aspartate (NMDA) and non-NMDA receptors on noxious stimulation-induced Fos expression in the rat spinal cord.


METHODS
Formalin (2%) was injected s.c. into one hindpaw of the rat. Fos expression was exhibited by immunocytochemical technique.


RESULTS
Two hours after s.c. formalin, Fos-like immunoreactive (FLI) neurons were distributed mainly in medial part of the lamina I and the outer lamina II of the ipsilateral dorsal horn. dl-2-Amino-5-phosphonovalerate (APV) administered intrathecally (10 microL, 0.01, 0.1, or 1 g.L-1) before injection of formalin into a hindpaw reduced the number of FLI neurons dose-dependently in the dorsal horn (P < 0.01), while 6,7-dinitroquinoxaline-2, 3(1H,4H)-dione (DNQX) (1 g.L-1) was ineffective.


CONCLUSIONS
NMDA receptor mediated noxious stimulation-induced Fos expression in the rat spinal cord.
Tao
Y X
YX
Shanghai Brain Research Institute, Chinese Academy of Sciences, China.
Zhao
Z Q
ZQ
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde; D008297:Male; D009474:Neurons / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism; D010146:Pain / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D013116:Spinal Cord / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D005557:Formaldehyde; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate