Influence of taurine on the electrically regulated ionic channels of the somatic membrane of neurons of the pond snail.

The influence of taurine (in concentrations of 10(-8) to 10(-2) mole/liter) on the fast sodium, calcium, and potassium, the slow potassium, and the leakage currents of the somatic membrane of the neurons of the pond snail was investigated. A monotonic decrease was demonstrated in the calcium and the slow potassium currents with an increase in the concentration of taurine. The sodium currents increased at taurine concentrations of 10(-8)-10(-4) mole/liter, while at concentrations of 10(-3)-10(-2) mole/liter they decreased. The fast potassium currents remained essentially unchanged at all concentrations of taurine. The leakage currents of the membrane at small concentrations of taurine decreased somewhat, and increased insignificantly at higher concentrations of it. All of the effects of taurine were reversible. It is hypothesized that the mechanism of the neuromodulatory, anticonvulsant, antihypoxic effects of taurine is at its base associated with changes in the electrically regulated ionic channels of the cell membrane.