Oxytocin mediates stress‐induced analgesia in adult mice
| Autor: | Susan J. Kim, L. J. Muglia, Ping Li, S. K. Vogt, Min Zhuo, D. A. Robinson, G. D. Wang, Feng Wei |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Patch-Clamp Techniques Physiology Blotting Western Oxytocin Synaptic Transmission Oxytocin Antagonist Membrane Potentials Mice Postsynaptic potential Internal medicine medicine Noxious stimulus Animals Neurons Afferent In Situ Hybridization Swimming Pain Measurement Mice Knockout Behavior Animal Reverse Transcriptase Polymerase Chain Reaction Chemistry Immunohistochemistry Research Papers Oxytocin receptor Electrophysiology Posterior Horn Cells Nociception Endocrinology Spinal Cord Hypothalamus Excitatory postsynaptic potential Analgesia Neuroscience Stress Psychological hormones hormone substitutes and hormone antagonists Paraventricular Hypothalamic Nucleus medicine.drug |
| Zdroj: | The Journal of Physiology. 540:593-606 |
| ISSN: | 1469-7793 0022-3751 |
| DOI: | 10.1113/jphysiol.2001.013492 |
| Popis: | As a neurohormone and as a neurotransmitter, oxytocin has been implicated in the stress response. Descending oxytocin-containing fibres project to the dorsal horn of the spinal cord, an area important for processing nociceptive inputs. Here we tested the hypothesis that oxytocin plays a role in stress-induced analgesia and modulates spinal sensory transmission. Mice lacking oxytocin exhibited significantly reduced stress-induced antinociception following both cold-swim (10 degrees C, 3 min) and restraint stress (30 min). In contrast, the mice exhibited normal behavioural responses to thermal and mechanical noxious stimuli and morphine-induced antinociception. In wild-type mice, intrathecal injection of the oxytocin antagonist dOVT (200 microM in 5 microl) significantly attenuated antinociception induced by cold-swim. Immunocytochemical staining revealed that, in the mouse, oxytocin-containing neurones in the paraventricular nucleus of the hypothalamus are activated by stress. Furthermore, oxytocin-containing fibres were present in the dorsal horn of the spinal cord. To test whether descending oxytocin-containing fibres could alter nociceptive transmission, we performed intracellular recordings of dorsal horn neurones in spinal slices from adult mice. Bath application of oxytocin (1 and 10 microM) inhibited excitatory postsynaptic potentials (EPSPs) evoked by dorsal root stimulation. This effect was reversed by the oxytocin antagonist dOVT (1 microM). Whole-cell recordings of dorsal horn neurones in postnatal rat slices revealed that the effect of oxytocin could be blocked by the addition of GTP-gamma-S to the recording pipette, suggesting activation of postsynaptic oxytocin receptors. We conclude that oxytocin is important for both cold-swim and restraint stress-induced antinociception, acting by inhibiting glutamatergic spinal sensory transmission. |
| Databáze: | OpenAIRE |
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