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In-Vivo Calcium Imaging of Sensory Neurons in the Rat Trigeminal Ganglion
Published on: February 9, 2024
Differential Changes in TRPV1 expression after trigeminal sensory nerve injury
Hyun Yeong Kim1, Chul-Kyu Park, Ik-Hyun Cho
1Department of Physiology and Program in Molecular and Cellular Neuroscience, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea.
The Journal of Pain
|January 30, 2008
Summary
Trigeminal nerve injury in rats increases TRPV1 expression in uninjured neurons, contributing to neuropathic pain. This suggests TRPV1 as a potential therapeutic target for pain management.
Area of Science:
- Neuroscience
- Pain Research
- Trigeminal Nerve Injury Models
Background:
- Inferior alveolar and mental nerve injury in rats is a validated model for trigeminal neuropathic pain.
- Neuronal loss in the trigeminal ganglion (TG) does not correlate with pain hypersensitivity in this model.
- Transient Receptor Potential Vanilloid 1 (TRPV1) is a key pain transducer involved in inflammatory and thermal pain perception.
Purpose of the Study:
- To investigate changes in TRPV1 expression in injured and uninjured TG neurons following trigeminal nerve injury.
- To correlate TRPV1 expression with observed pain hypersensitivity at 3 days post-surgery.
Main Methods:
- Immunohistochemical analysis was used to assess TRPV1 and Activating Transcription Factor 3 (ATF3) expression.
- Injured neurons were identified by ATF3 nuclear immunoreactivity.
- Analysis was performed at 3 and 60 days after surgery.
Main Results:
- ATF3 expression was localized to the nuclei of ipsilateral mandibular TG neurons, indicating injury.
- TRPV1 expression significantly increased in uninjured ipsilateral mandibular and maxillary TG neurons at 3 days post-injury.
- Both ATF3 and TRPV1 expression returned to basal levels by 60 days post-surgery.
Conclusions:
- Trigeminal sensory nerve injury induces differential TRPV1 expression changes in injured versus uninjured TG neurons.
- Upregulation of TRPV1 in uninjured TG neurons is associated with neuropathic pain development.
- TRPV1 represents a potential therapeutic target for treating neuropathic pain.
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