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Updated: Jan 17, 2026
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The Sciatic Nerve Cuffing Model of Neuropathic Pain in Mice
Published on: July 16, 2014
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Botulinum Neurotoxin A Signaling in Pain Modulation Within Human Sensory Neurons
Katherin A Gabriel1, Kali Hankerd1, Paulino Barragan-Iglesias2
1Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, Texas, USA.
Journal of Neurochemistry
|September 16, 2025
Summary
OnabotulinumtoxinA (onabotA) reduces pain by cleaving SNAP-25 in human sensory neurons, impairing neurotransmitter release. RNA sequencing reveals onabotA downregulates genes involved in neuronal signaling, offering new insights into its pain relief mechanisms.
Area of Science:
- Neuroscience
- Molecular Biology
- Pharmacology
Background:
- OnabotulinumtoxinA (onabotA) treats chronic migraine, but its mechanism in human sensory neurons is unclear.
- Rodent studies show BoNT/A cleaves SNAP-25, inhibiting neurotransmission and CGRP release.
- Previous human studies on BoNT/A's neuronal effects are limited.
Purpose of the Study:
- To elucidate the mechanism of action of onabotA in cultured human sensory neurons.
- To assess transcriptomic changes induced by onabotA treatment using RNA sequencing.
- To investigate the role of SV2C, SNAP25, and CALCA in onabotA's effects.
Main Methods:
- Human dorsal root ganglion (DRG) neurons were cultured and treated with onabotA.
- SNAP-25 cleavage and CGRP release were measured.
- Bulk RNA sequencing analyzed transcriptomic consequences of onabotA treatment.
- Immunohistochemistry and dataset mining validated target gene expression.
Main Results:
- SV2C expression in human DRG neurons overlapped with CGRP expression.
- OnabotA treatment led to SNAP-25 cleavage and reduced capsaicin-evoked CGRP release, indicating impaired SNARE complex function.
- RNA sequencing revealed downregulation of genes involved in neurotransmitter and neuropeptide release.
Conclusions:
- OnabotA disrupts SNARE complexes in human sensory neurons, reducing CGRP release.
- A novel mechanism involving downregulation of neurotransmission-related genes contributes to onabotA's pain-relieving effects.
- These findings provide molecular insights into onabotA's efficacy in human pain management.
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