THE effect of the neuroprotective drug, vinpocetine on the veratridine-evoked [Na+]iand [Ca2+]irise in isolated nerve terminals was studied. Vinpocetine, in a pharmacologically relevant concentration range (0.4–10 μM)ireduced the increase of [Na+]iinduced by veratridine (100 μM). The effect of the drug was concentration-dependent with 10 μM vinpocetine completely preventing the increase of [Na+]i. The [Ca2plus;]irise in response to veratridine was also prevented by vinpocetine. In addition, the [Ca2+]isignal induced by depolarization with 20 mM K+was reduced by vinpocetine (1–20 μM). This effect was not influenced by preincubation with 1 μM TTX and was also observed when Na+was replaced byN-methyl glucamine in the medium. It is concluded that vinpocetine is capable of inhibiting voltage-dependent Na+and Ca2+channels, respectively, and these effects might contribute to the neuroprotection exerted by the drug.