The role of taurine in the central nervous system and the modulation of intracellular calcium homeostasis.

The effects of taurine in the mammalian nervous system are numerous and varied. There has been great difficulty in determining the specific targets of taurine action. The authors present a review of accepted taurine action and highlight recent discoveries regarding taurine and calcium homeostasis in neurons. In general there is a consensus that taurine is a powerful agent in regulating and reducing the intracellular calcium levels in neurons. After prolonged L-glutamate stimulation, neurons lose the ability to effectively regulate intracellular calcium. This condition can lead to acute swelling and lysis of the cell, or culminate in apoptosis. Under these conditions, significant amounts of taurine (mM range) are released from the excited neuron. This extracellular taurine acts to slow the influx of calcium into the cytosol through both transmembrane ion transporters and intracellular storage pools. Two specific targets of taurine action are discussed: Na(+)-Ca2+ exchangers, and metabotropic receptors mediating phospholipase-C.