Effects of microinjection of OFQ into PAG on spinal dorsal horn WDR neurons in rats

Brain Res. 2001 Jan 5;888(1):167-171. doi: 10.1016/s0006-8993(00)03100-0.

Abstract

The aim of the present study was to examine the effect of microinjection of orphanin FQ (OFQ) into periaqueductal gray (PAG) on sensory processing in the wide dynamic range (WDR) neurons of the spinal dorsal horn and to explore the effect of OFQ on a descending system of pain modulation. The results show that microinjection of OFQ into ipsilateral PAG significantly facilitated C-fibre evoked response and post-discharge of spinal dorsal horn WDR neurons. This is consistent with our previous results obtained in behavioral studies. It suggests that the supraspinal effect of OFQ on pain may partly be mediated by PAG neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dose-Response Relationship, Drug
  • Electric Stimulation
  • Electrophysiology
  • Evoked Potentials / drug effects
  • Evoked Potentials / physiology
  • Microinjections
  • Nerve Fibers / drug effects
  • Nerve Fibers / physiology*
  • Nerve Fibers, Myelinated / drug effects
  • Nerve Fibers, Myelinated / physiology
  • Nociceptin
  • Opioid Peptides / pharmacology*
  • Pain / physiopathology
  • Periaqueductal Gray / cytology*
  • Periaqueductal Gray / drug effects
  • Periaqueductal Gray / physiology
  • Posterior Horn Cells / cytology
  • Posterior Horn Cells / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Vasodilator Agents / pharmacology*

Substances

  • Opioid Peptides
  • Vasodilator Agents