The aim of this study was to determine the effect and mechanism of low concentration of lidocaine on subthreshold membrane potential oscillations (SMPO) and burst discharges in chronically compressed dorsal root ganglion (DRG) neurons. DRG neurons were isolated by enzymatic dissociation method. SMPO, burst discharges and single spike were elicited by whole cell patchclamp technique in current clamp mode. Persistent Na+ current (INaP) and transient Na+ current (INaT) were elicited in voltage clamp mode. The results showed that SMPO was suppressed and burst discharges were eliminated by tetrodotoxin (TTX, 0.2 µmol/l) in current clamp mode, INaP was blocked by 0.2 µmol/l TTX in voltage clamp mode. SMPO, burst discharges and INaP were also suppressed by low concentration of lidocaine (10 µmol/l) respectively. However, single spike and INaT could only be blocked by high concentration of lidocaine (5 mmol/l). From these results, it is suggested that INaP mediates the generation of SMPO in injured DRG neurons. Low concentration of lidocaine (10 µmol/l) suppresses SMPO by selectively inhibiting INaP, but not INaT, in chronically compressed DRG neurons.

• Keywords
• Lidocaine, Neuropathic pain, Dorsal root ganglion, Ectopic discharges, Subthreshold membrane potential oscillations, Persistent Na+ current,
• MeSH
• Anesthetics, Local pharmacology   MeSH
• Sodium Channel Blockers MeSH
• Electrophysiology MeSH
• Financing, Organized MeSH
• Data Interpretation, Statistical MeSH
• Rats MeSH
• Lidocaine pharmacology   MeSH
• Membrane Potentials drug effects   MeSH
• Patch-Clamp Techniques MeSH
• Neurons metabolism   drug effects   MeSH
• Rats, Sprague-Dawley MeSH
• Sodium Channels metabolism   drug effects   MeSH
• Ganglia, Spinal cytology   metabolism   drug effects   MeSH
• Tetrodotoxin pharmacology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH