Neuropeptide Y acts at Y1 receptors in the rostral ventral medulla to inhibit neuropathic pain

Bradley K. Taylor, Sarang S. Abhyankar, Ngoc Tram T. Vo, Christopher L. Kriedt, Sajay B. Churi, Janice H. Urban

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

Brain microinjection studies in the rat using local anesthetics suggest that the rostral ventral medulla (RVM) contributes to the facilitation of neuropathic pain. However, these studies were restricted to a single model of neuropathic pain (the spinal nerve ligation model) and to just two stimulus modalities (non-noxious tactile stimulus and heat). Also, few neurotransmitter systems have been shown to modulate descending facilitation. After either partial sciatic nerve ligation (PSNL) or spared nerve injury (SNI), we found that unilateral or bilateral microinjection of lidocaine into the RVM reduced not only mechanical allodynia (decreased threshold to von Frey hairs and/or an automated device) and mechanical hyperalgesia (increased paw lifting in response to a noxious pin), but also cold hypersensitivity (increased lifting in response to the hindpaw application of a drop of acetone). Application of a drop of water did not elicit paw withdrawal, indicating that the acetone test is indeed a measure of cold hypersensitivity. We found significant neuropeptide Y Y1-like immunoreactivity within, and lateral to, the midline RVM. Intra-RVM injection of neuropeptide Y (NPY) dose-dependently inhibited the mechanical and cold hypersensitivity associated with PSNL or SNI, an effect that could be blocked by the Y1 receptor antagonist BIBO 3304. We conclude that medullary facilitation spans multiple behavioral signs of allodynia and hyperalgesia in multiple models of neuropathic pain. Furthermore, NPY inhibits behavioral signs of neuropathic pain, possibly by acting at Y1 receptors in the RVM.

Original languageEnglish (US)
Pages (from-to)83-95
Number of pages13
JournalPain
Volume131
Issue number1-2
DOIs
StatePublished - Sep 2007

Bibliographical note

Funding Information:
The study was supported by NIH grants DA10356 and NS45954 to BKT.

Keywords

  • Allodynia
  • Descending facilitation
  • Hyperalgesia
  • Lidocaine
  • Rat
  • Spared nerve injury

Fingerprint Dive into the research topics of 'Neuropeptide Y acts at Y1 receptors in the rostral ventral medulla to inhibit neuropathic pain'. Together they form a unique fingerprint.

Cite this