Altered membrane excitability following increased levels of homocysteine

Treatment with enzyme-inducting anticonvulsant drugs has been shown to be associated with increased blood levels of homocysteine. We hypothesize that elevated homocysteine levels can alter the membrane excitability of neurons, thereby altering the propensity for seizures. To address this issue, we examined primary cultures of hippocampal neurons with the whole-cell patch-clamp technique. Homocysteine was applied intracellularly (100µM) via the patch pipette, or cell cultures were incubated with 100µM homocysteine for 24h. Membrane voltage was measured in current-clamp mode and action potential firing was induced…