Related Experiment Video

Updated: Feb 28, 2026

Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
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Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities

Published on: July 29, 2014

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Toll-like Receptor-Dependent Negative Effects of Opioids: A Battle between Analgesia and Hyperalgesia

Masaud Shah1, Sangdun Choi1

  • 1Department of Molecular Science and Technology, Ajou University, Suwon, South Korea.

Frontiers in Immunology
|June 17, 2017
PubMed

Insights

Glia and toll-like receptors (TLRs) are key in neuropathic pain and affect opioid effectiveness. Targeting these pathways requires considering both pain relief and pain worsening effects of analgesics.

Area of Science:

  • Neuroscience
  • Immunology
  • Pharmacology

Background:

  • Pathophysiology of pathological pain and analgesic pharmacology have advanced significantly.
  • Glia and toll-like receptors (TLRs) are implicated in neuropathic pain development and opioid analgesia.
  • Neuroimmune interface cells expressing TLRs play a crucial role in pain signaling.

Purpose of the Study:

  • To review molecular mechanisms of pain initiation and progression.
  • To examine the role of TLRs in neuropathic pain.
  • To elucidate the mechanisms of morphine and morphine-3-glucuronide in TLR-dependent signaling.

Main Methods:

  • Comprehensive literature review of molecular mechanisms.
  • Analysis of TLRs' role in pain pathways.
  • Examination of opioid interactions with TLR-mediated signaling.

Main Results:

  • Glia and TLRs are central to neuropathic pain and opioid efficacy.
  • Opioids exhibit both analgesic and analgesia-opposing effects.
  • TLR-mediated signaling influences central immune responses to pain.

Conclusions:

  • Targeting glia for neuropathic pain requires understanding complex opioid effects.
  • Opioid actions in TLR-mediated signaling are critical for pain management.
  • Future strategies must account for dual opioid effects in neuropathic pain treatment.
Keywords:
hyperalgesiamorphineopioidpaintoll-like receptor

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