High potassium, veratridine and electrically induced release of taurine from the cerebellar cortex.

In the in vivo superfused cerebellar cortex of anaesthetized rats, the following stimuli were effective in evoking large increases of isotopically labelled taurine from preloaded tissue: high (40 mM) K+; rectangular, 0.1 msec electrical pulses at 1.5 mA and 500 Hz; the depolarizing veratrum alkaloid, veratridine (0.5 x 10(-5) M) and scorpion venom (10(-6) g.ml-1). Both the high K+ and electrically evoked effluxes were markedly Ca2+ dependent; the veratridine response was abolished in the presence of tetrodotoxin (10(-6) g.ml-1). The data indicate that taurine is being released from excitable cells rather than neuroglia and may therefore have some neurotransmitter-like role in the cerebellum.