신경병증성통증 모델쥐에서 뇌간핵 부위에 미세 주입한 Bicuculline에 의한 척수후각세포의반응도 억제 = Suppression by Microinjection of Bicuculline into Brain Stem Nuclei of Dorsal Horn Neuron Responsiveness in Neuropathic Rats신경병증성통증 모델쥐에서 뇌간핵 부위에 미세 주입한 Bicuculline에 의한 척수후각세포의반응도 억제

다국어 초록 (Multilingual Abstract)

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다국어 초록 (Multilingual Abstract)

Background: The present study was conducted to investigate effects of mieroinjection of bicuculline, GABA-A receptor antagonist, into the brain stem nuclei on the dorsal horn neuron responsiveness in rats with an experimental peripheral neuropsthy.
Methods: An experimental neuropathy was induced by a unilateral ligation of L5-L6 spinal nerves of rats. After 2-3 weeks after the surgery, single-unit recording was made from wide dynamic range (WDR) neurons in the spinal cord dorsal horn.
Results: Responses of WDR neurons to both noxious and innocuous mechanical stimuli applied to the somatic reeeptive fields were enhanced on the nerve injured side. These enhanced responsiveness of WDR neurons were suppressed by microinjection of bicuculline into periaqueductal gray(PAG) or nucleus reticularis gigantocellularis(Gi). A similar suppression was also observed when morphine was microinjected into PAG or Gi. Suppressive actian by Gi-bicuculline was reversed by naloxonazine, p -opioid receptor antagonist, microinjected into PAG whereas PAG-bicuculline induced suppression was not affected by naloxonazine injection into Gi. Gi-bicuculline induced suppression were reversed by a transection of dorsolateral funiculus(DLF) of the spinal cord.
Conclusions: The results suggest that endogenous opioids, via acting on GABAergic interneurons in PAG and Gi, may be involved in the control of neuropathic pain by activating the descending inhibitory pathways that project to the spinal dorsal horn through DLF to inhibit the responsiveness of WDR neurons.