A novel analgesic approach to optogenetically and specifically inhibit pain transmission using TRPV1 promoter

Brain Res. 2015 Jun 3;1609:12-20. doi: 10.1016/j.brainres.2015.03.008. Epub 2015 Mar 20.

Abstract

Chronic pain is a pathological condition that results in significant loss of life quality, but so far no specific treatment for chronic pain has been developed. Currently available analgesia drugs are either not specific enough or have severe side effects. Therefore a non-invasive approach with high specificity to inhibit nociception becomes essential. In this study, a recombinant virus (AAV5-TRPV1-ArchT-eGFP) was constructed and injected into the mouse dorsal root ganglion (DRG). The Transient Receptor Potential Vanilloid type 1 (TRPV1) channel promoter was used to selectively express inhibitory light-sensitive pump ArchT (the archaerhodopsin from Halorubrum strain TP009) in nociceptive DRG neurons. The successful transfer of ArchT gene was confirmed by a robust expression of green florescent protein in the DRG neurons. In vivo behavioral tests demonstrated that both the mechanical paw withdrawal threshold and the radiant heat evoked paw withdrawal latency were significantly increased upon illumination by a 532 nm green laser light to the paw of a viral-vector injected mice, while the same laser light did not induce any observable change in naïve mice. In conclusion, we have established a novel analgesic approach that can noninvasively and selectively inhibit pain transmission using an acute and controllable optogenetics method. This study may shed light on the application of a novel optogenetic strategy for the treatment of pain.

Keywords: Analgesic; ArchT; Nociceptor; Optogenetic; Pain; TRPV1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Archaeal Proteins / genetics
  • Archaeal Proteins / metabolism*
  • Dependovirus / genetics
  • Ganglia, Spinal / metabolism
  • Genetic Vectors
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • Halorubrum
  • Hot Temperature
  • Humans
  • Lasers
  • Mice
  • Mice, Inbred C57BL
  • Nociceptors / metabolism
  • Optogenetics / methods*
  • Pain / metabolism
  • Pain Management / methods*
  • Pain Threshold / physiology
  • Promoter Regions, Genetic*
  • TRPV Cation Channels / genetics*
  • Touch

Substances

  • Archaeal Proteins
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • archaerhodopsin protein, Archaea
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins