ArticleThe Journal of physiology2019
μ-Opioid receptors in primary sensory neurons are essential for opioid analgesic effect on acute and inflammatory pain and opioid-induced hyperalgesia.
Article in The Journal of physiology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 49 papers.
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Who cites it
49 citing papers in PubMed, 76 citations in OpenAlex.
- EphB1 Receptor Blockade Augments Morphine Antinociception via Inhibiting GRK2-Mediated µ-Opioid Receptor Internalization.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2026Article
- Sensory neuron BRAF mediates opioid-induced hyperalgesia and tolerance via presynaptic NMDA receptor hyperactivity.The Journal of clinical investigation · 2026Article
- Article
- The nociceptor primary cilium.Brain : a journal of neurology · 2026Review
- EGFR activation sensitizes trigeminal NMDA receptors to promote pain and morphine analgesic tolerance in oral cancer.Science signaling · 2026Article
- LRRC8A constitutively inhibits pain hypersensitivity in rodent models by restraining NMDA receptor activity at spinal cord synapses.Science translational medicine · 2025Article
- GαScience signaling · 2025Article
- α2δ-1-Linked NMDA and AMPA Receptors in Neuropathic Pain and Gabapentinoid Action.Journal of neurochemistry · 2025Review
- Molecular Anatomy of Synaptic and Extrasynaptic Neurotransmission Between Nociceptive Primary Afferents and Spinal Dorsal Horn Neurons.International journal of molecular sciences · 2025Review
- Histone Methyltransferase G9a in Primary Sensory Neurons Promotes Inflammatory Pain and Transcription ofThe Journal of neuroscience : the official journal of the Society for Neuroscience · 2025Article
- Interactions of pain and opioids on conditioned place preference in rodents.Psychopharmacology · 2025Review
- FLT3 signaling inhibition abrogates opioid tolerance and hyperalgesia while preserving analgesia.Nature communications · 2024Article
- Calcineurin and CK2 Reciprocally Regulate Synaptic AMPA Receptor Phenotypes via α2δ-1 in Spinal Excitatory Neurons.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2024Article
- Opioid-Induced Hyperalgesia and Tolerance Are Driven by HCN Ion Channels.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2024Article
- Constitutive KCC2 Cell- and Synapse-Specifically Regulates NMDA Receptor Activity in the Spinal Cord.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2024Article
- The psychophysiology of music-based interventions and the experience of pain.Frontiers in psychology · 2024Review
- Polyphenols and extracts fromFrontiers in pharmacology · 2024Article
- Cell-type specific molecular architecture for mu opioid receptor function in pain and addiction circuits.Neuropharmacology · 2023Review
- mGluR5 from Primary Sensory Neurons Promotes Opioid-Induced Hyperalgesia and Tolerance by Interacting with and Potentiating Synaptic NMDA Receptors.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2023Article
- NMDA Receptors at Primary Afferent-Excitatory Neuron Synapses Differentially Sustain Chemotherapy- and Nerve Trauma-Induced Chronic Pain.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2023Article
Corrections and comments
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Authors and funding
4 authors at 1 institution in 2 countries.
Funding
Abstract
key pointsμ-Opioid receptors (MORs) are expressed peripherally and centrally, but the loci of MORs responsible for clinically relevant opioid analgesia are uncertain. Crossing Oprm1 ABSTRACT: The pain and analgesic systems are complex, and the actions of systemically administered opioids may be mediated by simultaneous activation of μ-opioid receptors (MORs, encoded by the Oprm1 gene) at multiple, interacting sites. The loci of MORs and circuits responsible for systemic opioid-induced analgesia and hyperalgesia remain unclear. Previous studies using mice in which MORs are removed from Nav1.8- or TRPV1-expressing neurons provided only an incomplete and erroneous view about the role of peripheral MORs in opioid actions in vivo. In the present study, we determined the specific role of MORs expressed in primary sensory neurons in the analgesic and hyperalgesic effects produced by systemic opioid administration. We generated Oprm1 conditional knockout (Oprm1-cKO) mice in which MOR expression is completely deleted from dorsal root ganglion neurons and substantially reduced in the spinal cord, which was confirmed by immunoblotting and immunocytochemical labelling. Both opioid-induced inhibition and potentiation of primary sensory input were abrogated in Oprm1-cKO mice. Remarkably, systemically administered morphine potently inhibited acute thermal and mechanical nociception and persistent inflammatory pain in control mice but had little effect in Oprm1-cKO mice. The analgesic effect of intrathecally administered morphine was also profoundly reduced in Oprm1-cKO mice. Additionally, chronic morphine treatment-induced hyperalgesia was absent in Oprm1-cKO mice. Our findings directly challenge the notion that clinically relevant opioid analgesia is mediated mostly by centrally expressed MORs. MORs in primary sensory neurons, particularly those expressed presynaptically at the first sensory synapse in the spinal cord, are crucial for both opioid analgesia and opioid-induced hyperalgesia.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.