Vitamin B2 inhibits glutamate release from rat cerebrocortical nerve terminals

We examined the effect of ribo£avin, vitamin B2, on the release of endogenous glutamate fromnerve terminals puri¢ed fromrat cerebral cortex.The release of glutamate evoked by 4-aminopyridine was inhibited by ribo£avin. Further experiments indicated that ribo£ avin-mediated inhibition of glutamate release (i) results from a reduction of vesicular exocytosis, not from an inhibition of nonvesicular release; (ii) is associated with a decrease in presynaptic Ntype and P/Q-type voltage-dependent Ca2+ channel activity.These ¢ndings are the ¢rst to suggest that, in rat cerebrocortical nerve terminals, ribo£avin suppresses voltage-dependent Ca2+ channel activity and in so doing inhibits evokedglutamate release.This ¢nding may explain the neuroprotective effects of vitamin B2 against neurotoxicity. NeuroReport 19:1335-1338