Pulsed Radiofrequency Decreases pERK and Affects Intracellular Ca2+ Influx, Cytosolic ATP Level, and Mitochondrial Membrane Potential in the Sensitized Dorsal Root Ganglion Neuron Induced by N-Methyl D-Aspartate

Background: The molecular mechanism of pulsed radiofrequency (PRF) in chronic pain management is not fully understood. Chronic pain involves the activation of specific N-Methyl D-Aspartate receptors (NMDAR) to induce central sensitization. This study aims to determine the effect of PRF on central sensitization biomarker phosphorylated extracellular signal-regulated kinase (pERK), Ca2+ influx, cytosolic ATP level, and mitochondrial membrane potential (Delta psi m) of the sensitized dorsal root ganglion (DRG) neuron following NMDAR activation. Methods: This study is a true experimental in-vitro study on a sensitized DRG neuron induced with 80 mu M NMDA. There are six treatment groups including control, NMDA 80 mu M, Ketamine 100 mu M, PRF 2Hz, NMDA 80 mu M + PRF 2 Hz, and NMDA 80 mu M + PRF 2 Hz + ketamine 100 mu M. We use PRF 2 Hz 20 ms for 360 seconds. Statistical analysis was performed using the One-Way ANOVA and the Pearson correlation test with alpha=5%. Results: In the sensitized DRG neuron, there is a significant elevation of pERK. There is a strong correlation between Ca2+, cytosolic ATP level, and Delta psi m with pERK intensity (p<0.05). PRF treatment decreases pERK intensity from 108.48 +/- 16.95 AU to 38.57 +/- 5.20 AU (p<0.05). PRF exposure to sensitized neurons also exhibits a Ca2+ influx, but still lower than in the unexposed neuron. PRF exposure in sensitized neurons has a higher cytosolic ATP level (0.0458 +/- 0.0010 mM) than in the unexposed sensitized neuron (0.0198 +/- 0.0004 mM) (p<0.05). PRF also decreases Delta psi m in the sensitized neuron from 109.24 +/- 6.43 AU to 33.21 +/- 1.769 AU (p<0.05). Conclusion: PRF mechanisms related to DRG neuron sensitization are by decreasing pERK, altering Ca2+ influx, increasing cytosolic ATP level, and decreasing Delta psi m which is associated with neuron sensitization following NMDAR activation.

Automated summary

This study investigates the effects of pulsed radiofrequency (PRF) on central sensitization in chronic pain management. The findings suggest that PRF alleviates neuron sensitization by reducing pERK, modulating Ca2+ influx, increasing cytosolic ATP level, and decreasing Delta psi m.