The effects of gabapentin on different ligand- and voltage-gated currents in isolated cortical neurons

A clear picture of the mechanisms of action of the anti-epileptic agent gab apentin is far from being accomplished. We have analyzed the effects of gab apentin on ligand- and voltage-gated currents in isolated adult rat cortica l neurons. Gabapentin failed to modify glutamate currents and produced a sl ight reduction of GABA responses. Negligible inhibition of sodium, but cons istent inhibition of high-voltage-activated calcium conductance was promote d by gabapentin. In addition, gabapentin reduced calcium current sensitivit y to dihydropyridine agonist and antagonists. Interestingly, gabapentin als o decreased a not-inactivating. cadmium-sensitive, potassium current. These unconventional effects might underlie its efficacy in a variety of disease s which involve periodic discharge patterns as neuropathic pain or essentia l tremor. (C) 2001 Elsevier Science B.V. All rights reserved.