Abeta-afferents activate neurokinin-1 receptor in dorsal horn neurons after nerve injury.
We provide new evidence demonstrating that peripheral nerve injury produces profound alterations in synaptic input to dorsal horn neurons mediated by non-nociceptive sensory neurons, and activation of neurokinin-1 receptor may be involved in the enhanced synaptic response and thus contribute to the tactile allodynia. Our results show that Abeta-fiber-evoked field potential significantly increased in the first postoperative week and decreased thereafter while maximal mechanical allodynia was exhibited. The neurokinin-1 receptor antagonist L703,606 significantly reduced Abeta-fiber-evoked field potential in nerve-injured but not in sham-operated animals. The non-N-methyl-D-aspartate receptor antagonist CNQX inhibited Abeta-fiber-evoked field potential in both nerve-injured and sham-operated rats, while the N-methyl-D-aspartate receptor antagonist MK-801 did not affect Abeta-fiber-evoked field potential in either CCI or sham-operated animals.
Zheng
Ji-Hong
JH
Department of Neurobiology, Parker College Research Institute, 2500 Walnut Hill Lane, Dallas, TX 75229, USA.
Song
Xue-Jun
XJ
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006930:Hyperalgesia / Q000503:physiopathology; D008026:Ligation; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D010812:Physical Stimulation; D020671:Posterior Horn Cells / Q000166:cytology / Q000502:physiology*; D011812:Quinuclidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D018040:Receptors, Neurokinin-1 / Q000502:physiology*; D020426:Sciatic Neuropathy / Q000503:physiopathology*
D018691:Excitatory Amino Acid Antagonists; D011812:Quinuclidines; D016194:Receptors, N-Methyl-D-Aspartate; D018040:Receptors, Neurokinin-1; C076851:L 703606; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione