Open AccessLidocaine suppresses subthreshold oscillations by inhibiting persistent Na+ current in injured dorsal root ganglion neurons
Author(s) -
Hongyan Dong,
Y-H. Fan,
Wang Yy,
Wen-Tao Wang,
Hu Sj
Publication year - 2008
Publication title -
physiological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.647
H-Index - 70
eISSN - 1802-9973
pISSN - 0862-8408
DOI - 10.33549/physiolres.931164
Subject(s) - dorsal root ganglion , tetrodotoxin , current clamp , lidocaine , chemistry , biophysics , patch clamp , voltage clamp , electrophysiology , anesthesia , membrane potential , endocrinology , medicine , dorsum , anatomy , biology , biochemistry
The aim of this study was to determine the effect and mechanismof low concentration of lidocaine on subthreshold membranepotential oscillations (SMPO) and burst discharges in chronicallycompressed dorsal root ganglion (DRG) neurons. DRG neuronswere isolated by enzymatic dissociation method. SMPO, burstdischarges 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 voltageclamp mode. The results showed that SMPO was suppressed andburst discharges were eliminated by tetrodotoxin (TTX,0.2 μmol/l) in current clamp mode, INaP was blocked by0.2 μmol/l TTX in voltage clamp mode. SMPO, burst dischargesand INaP were also suppressed by low concentration of lidocaine(10 μmol/l) respectively. However, single spike and INaT couldonly be blocked by high concentration of lidocaine (5 mmol/l).From these results, it is suggested that INaP mediates thegeneration of SMPO in injured DRG neurons. Low concentrationof lidocaine (10 μmol/l) suppresses SMPO by selectively inhibitingINaP, but not INaT, in chronically compressed DRG neurons.