N-Methyl- d-aspartate (NMDA) and non-NMDA glutamate receptor antagonists differentially suppress dorsal horn neuron responses to mechanical stimuli in rats with peripheral nerve injury

• Published in: Neuroscience letters Vol. 211; no. 1; pp. 37 - 40
• Main Authors: Leem, Joong Woo, Choi, Eun Jin, Park, Eun Sun, Paik, Kwang Se
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 14-06-1996; Elsevier
• Subjects: 2-Amino-5-phosphonovalerate - pharmacology; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid - administration & dosage; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid - pharmacology; Animals; Antinociception; Biological and medical sciences; Central nervous system; Dorsal horn neuron; Electrophysiology; Excitatory amino acid; Excitatory Amino Acid Agonists - administration & dosage; Excitatory Amino Acid Agonists - pharmacology; Excitatory Amino Acid Antagonists - pharmacology; Fundamental and applied biological sciences. Psychology; Iontophoresis; Male; N-Methylaspartate - administration & dosage; N-Methylaspartate - pharmacology; Neurons - drug effects; Neurons - physiology; Neuropathic pain; Peripheral Nerve Injuries; Physical Stimulation; Quinoxalines - pharmacology; Rats; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate - antagonists & inhibitors; Spinal Cord - drug effects; Spinal Cord - physiology; Vertebrates: nervous system and sense organs; Wide dynamic range; Dorsal horn neuron; Antinociception; Excitatory amino acid; Wide dynamic range; Neuropathic pain; Peripheral nerve; Spinal cord; Rat; Rodentia; Central nervous system; Electrophysiology; Glutamate receptor; Posterior spinal horn; Analgesia; Vertebrata; Mammalia; Antagonist; Lesion; Mechanical stimulus; NMDA receptor
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/0304-3940(96)12714-2

The effects of iontophoretically ejected glutamate receptor antagonists on mechanically evoked responsiveness were examined on wide dynamic range (WDR) dorsal horn neurons in anesthetized rats that received a unilateral ligation of the L5 and L6 spinal nerves 10–15 days previously. Both brush- and pinch-evoked responses of dorsal horn neurons on the nerve-injured side were enhanced.
N-Methyl-
d-aspartate (NMDA) receptor antagonist, 2-amino-5-phosphonopentanoic acid (AP5), preferentially suppressed the enhanced pinch-evoked response, whereas (
RS)-α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptor selective antagonist, 6-nitro-7-sylphamoylbenzo(
f)quinoxaline-2,3-dione (NBQX), preferentially attenuated the enhanced brush-evoked response. The results indicate that the enhanced responses to noxious and non-noxious peripheral inputs induced in WDR dorsal horn neurons following the nerve injury are mediated by activation of NMDA and AMPA receptors, respectively.