NMDA and AMPA/KA receptors are involved in the c-Fos expression following mustard oil activation of C-fibres.
To examine whether mustard oil application to the skin activated c-Fos via glutamate receptors, a competitive NMDA receptor antagonist, 3-(2-carboxpiperazin-4-yl)propyl-1-phospionic acid (CPP), a selective AMPA/KA receptor antagonist, 6-cyano-2,3-dihydroxy-7-nitro-quinoxaline (CNQX), or both, were used intrathecally 10 min prior to noxious stimulation. Application of mustard oil to left hind foot of the vehicle-injected animals produced c-Fos expression mainly in superficial laminae (laminae I-II) of the dorsal horn on the side ipsilateral to the stimulation. CPP significantly reduced the number of c-Fos-positive nuclei in superficial laminae. But significant reduction of c-Fos expression by CNQX was seen in deeper laminae (laminae III-X). Administration of both CPP and CNQX extensively reduced the number of c-Fos-positive cells in both superficial and deeper laminae. However, they did not greatly change the number of c-Fos-positive cells in lamina I. This experiment revealed that NMDA and AMPA/KA receptors contribute to the mustard oil-induced c-Fos expression in the spinal cord. These data also suggest that other neurotransmitter receptors might be involved in the activation produced by algesic chemical activation of C-fibre primary afferents.
Soygüder
Zafer
Z
Department of Anatomy, Veterinary Faculty, The University of Yüzüncü Yil, Van Turkey. zsoyguder@hotmail.com
D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D009149:Mustard Plant; D036421:Nerve Fibers, Unmyelinated / Q000187:drug effects / Q000378:metabolism*; D009434:Neural Pathways / Q000378:metabolism; D009619:Nociceptors / Q000187:drug effects / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology; D010938:Plant Oils; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000187:drug effects / Q000378:metabolism*; D018092:Kainic Acid Receptors / Q000187:drug effects / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism
D018691:Excitatory Amino Acid Antagonists; D010936:Plant Extracts; D010938:Plant Oils; D016760:Proto-Oncogene Proteins c-fos; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; C027793:mustard oil