Gabapentin selectively reduces persistent sodium current in injured type-A dorsal root ganglion neurons

Rui-Hua Yang, Wen-Ting Wang, Jing-Yuan Chen, Rou-Gang Xie, San-Jue Hu
Pain 2009, 143 (1-2): 48-55
It has been confirmed that the voltage-gated persistent sodium currents mediate the generation of subthreshold membrane potential oscillations (SMPOs) and contribute to shaping repetitive firing. Our previous study indicated that gabapentin (GBP) administration induced a dose-dependent inhibition of SMPO in chronically compressed dorsal root ganglion (CCD) neurons. To investigate the mechanisms and possible site(s) of action of GBP, the persistent sodium currents (I(NaP)) were measured and the effects of GBP on I(NaP) were examined in CCD neurons electrophysiologically in vitro. DRG neurons possess slow TTX-sensitive inactivating sodium currents that significantly contribute to the generation of membrane oscillations by amplifying the resonance behavior. GBP reduced the resonant amplitude of DRG neurons as well as inhibiting the firing and SMPO induced by injection current, which was strongly due to the inhibitory effect on persistent sodium currents. Furthermore, we found that GBP (1-20 microM) administration inhibited the persistent sodium currents in dose-dependent manner, while the changes of K(+) and Ca(2+) current minimally contributed to the effect of GBP on oscillation and resonant behavior of DRG neurons. In contrast, the amplitude and voltage-dependence of transient sodium current were unchanged by GBP. The results suggest that GBP decreased the amplitude of resonance and abolished the SMPO of A-type DRG neurons through the inhibition of I(NaP), and thus inhibited the SMPO dependent repetitive and bursting firings.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"