The neuroprotective role of nimodipine was tested in kainic acid (50 and 100 mu M) induced neurotoxicity in cerebellar granular cell cultures of 4 to 7 day-old rat pups. Nimodipine was applied in 50, 100 and 200 mu M concentrations. Kainate, in either dose, induced cerebellar granular cell death in respect to controls and the results were statistically significant (P = 0.000 for both doses). However, kainic acid in 100 mu M concentration led to higher rates of cell death than 50 mu M (P = 0.017). The neuroprotective role of nimodipine in kainate induced neurotoxicity was dose dependent. Kainate toxicity in 50 mu M concentration was blocked by 50 and 100 mu M nimodipine concentrations (P = 0.006 and P = 0.002, respectively) while 200 mu M nimodipine was found ineffective. The most effective nimodipine dose for 100 mu M kainic acid neurotoxicity was 200 mu M (P = 0.000) while 50 and 100 mu M concentrations of nimodipine were found ineffective. In this study, we have proven the dose-dependent neuroprotective role of nimodipine in kainate induced neurotoxicity in cerebellar granular cell cultures of rat pups.