신경병성통증 모델쥐의 척수내에서 흥분성 아미노산 수용체 길항체의 ?진통작용 |
이상암, 임중우,박은선, 최은진,남택상.백광세 |
울산대학교 신경과,연세대학교 생리학교실 |
Antinociceptive Actions of Excitatory
Amino Acid Recetor Antagonists in the
Spinal Cord of a Rat Model for Neuropathic Pain
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S.A. Lee, M.D., J.W. Leem, Ph. D., E.S. Park, M.S., E.J. Choi, M.S., T.S. Nam, M.D., K.S. Paik, M.D., |
Department of Neurology, University of Ulsan College of Medicine, Department of Physiology, Yonsei University College of Medicine |
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Abstract |
It has been proposed that excitatory amirio acid (EAA) receptors mediate sensitimtion of central neurons that may play a cruc ial role in the generation of neuropathic pain. We performed experiments using a rat model of peripheral neuropathy to provide direct evidence that EAA receptors are involved in mediating hyperexcitability of dorsal hom neurons in the spinal cord. The results obtained were as follows:
1)Rats that received an unilateral ligation of L5 and L6 spinal nerves showed
behaviorally increased mechanical sensitivity of the hindpaw m the side of nerve
2)Wide dynamic range (VVDR) spinal dorsal hom neurons on the side of the ligation
showed enhanced brush-and pinch-evoked responses.
3)WDR neurons on the side of the ligation were classified into three groups, based on
responses to iontophoretically applied EAA receptor ligands: neurons responsive
preferentially to NMDA (15 of 40, 37.5%), neurons responsive preferentially to ANPA
(20 of 40, 50%), non-NMDA receptor agonist, and neurons responsive well to
both NMDA and AMPA (5 of 40, 12.5%).
4)AMPA responsive neurons were suppressed by GAMS, non-NMDA receptor
antagonist, only in their brush-evoked response, whereas NMDA responsive neurons
were suppressed by AP-5, NMDA receptor antagonist, only in their pinch-evoked
response.
The results suggest that following a peripheral nerve injury, spinal WDR neurons are
enhanced in their mechanical responsiveness where increased response to innocuous
mechanical stimulus is mediated by non-NMDA receptor while that to noxious one is
by NMDA receptor. |
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