Are presynaptic GABA-Cρ2 receptors involved in anti-nociception?

Neurosci Lett. 2015 Oct 8;606:145-50. doi: 10.1016/j.neulet.2015.08.049. Epub 2015 Sep 7.

Abstract

We investigated the anti-nociceptive effects of GABA-C receptors in the central nervous system. Intracisternal injection of CACA, a GABA-C receptor agonist or isoguvacine, a GABA-A receptor agonist, significantly increased the tail-withdrawal latency. TPMPA, a GABA-C receptor antagonist blocked the effects of CACA but not isoguvacine indicating that GABA-C receptors are involved in regulating pain. Further, double-labelled immunofluorescence studies revealed that GABA-Cρ2 receptors are expressed presynaptically in the spinal dorsal horn, especially, substantia gelatinosa, a region that has been previously implicated in analgesia by regulating nociceptive inflow. These data provide a provenance for future work looking at presynaptic spinal GABA-C receptors in the control of nociception.

Keywords: Anti-nociception; Dorsal horn; GABA-C receptors; Pain; Spinal cord; Substantia gelatinosa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Crotonates / pharmacology
  • GABA-A Receptor Agonists / pharmacology
  • GABA-A Receptor Antagonists / pharmacology
  • Isonicotinic Acids / pharmacology
  • Male
  • Pain / metabolism*
  • Pain / physiopathology
  • Phosphinic Acids / pharmacology
  • Pyridines / pharmacology
  • Rats, Wistar
  • Receptors, GABA-A / metabolism*
  • Receptors, Presynaptic / antagonists & inhibitors
  • Receptors, Presynaptic / metabolism*
  • Substantia Gelatinosa / metabolism

Substances

  • (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid
  • Crotonates
  • GABA-A Receptor Agonists
  • GABA-A Receptor Antagonists
  • Gabrr2 protein, rat
  • Isonicotinic Acids
  • Phosphinic Acids
  • Pyridines
  • Receptors, GABA-A
  • Receptors, Presynaptic
  • isoguvacine