Conotoxin contulakin-G engages a neurotensin receptor 2/R-type calcium channel (Cav2.3) pathway to mediate spinal antinociception

Laurent Martin, Mohab Ibrahim, Kimberly Gomez, Jie Yu, Song Cai, Lindsey A. Chew, Shreya S. Bellampalli, Aubin Moutal, Tally Largent-Milnes, Frank Porreca, Rajesh Khanna, Baldomero M. Olivera, Amol Patwardhan

Research output: Contribution to journalArticlepeer-review


Intrathecal application of contulakin-G (CGX), a conotoxin peptide and a neurotensin analogue, has been demonstrated to be safe and potentially analgesic in humans. However, the mechanism of action for CGX analgesia is unknown. We hypothesized that spinal application of CGX produces antinociception through activation of the presynaptic neurotensin receptor (NTSR)2. In this study, we assessed the mechanisms of CGX antinociception in rodent models of inflammatory and neuropathic pain. Intrathecal administration of CGX, dose dependently, inhibited thermal and mechanical hypersensitivities in rodents of both sexes. Pharmacological and clustered regularly interspaced short palindromic repeats/Cas9 editing of NTSR2 reversed CGX-induced antinociception without affecting morphine analgesia. Electrophysiological and gene editing approaches demonstrated that CGX inhibition was dependent on the R-type voltage-gated calcium channel (Cav2.3) in sensory neurons. Anatomical studies demonstrated coexpression of NTSR2 and Cav2.3 in dorsal root ganglion neurons. Finally, synaptic fractionation and slice electrophysiology recordings confirmed a predominantly presynaptic effect. Together, these data reveal a nonopioid pathway engaged by a human-tested drug to produce antinociception.

Original languageEnglish (US)
Pages (from-to)1751-1762
Number of pages12
Issue number9
StatePublished - Sep 1 2022


  • Analgesia
  • Conotoxin
  • Intrathecal
  • Neurotensin receptor type 2
  • R-type voltage-gated calcium channel 2.3

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Anesthesiology and Pain Medicine


Dive into the research topics of 'Conotoxin contulakin-G engages a neurotensin receptor 2/R-type calcium channel (Cav2.3) pathway to mediate spinal antinociception'. Together they form a unique fingerprint.

Cite this