Activation of synaptic and extrasynaptic glycine receptors by taurine in preoptic hypothalamic neurons

Taurine is an essential amino-sulfonic acid having a fundamental function in the brain, participating in both cell volume regulation and neurotransmission. Using a whole cell voltage patch clamp technique, the taurine-activated neurotransmitter receptors in the preoptic hypothalamic area (PHA) neurons were investigated. In the first set of experiments, different concentrations of taurine were applied on PHA neurons. Taurine-induced responses were concentration-dependent. Taurine-induced currents were action potential-independent and sensitive to strychnine, suggesting the involvement of glycine receptors. In addition, taurine activated not only alpha-homomeric, but also alpha beta-heteromeric glycine receptors in PHA neurons. Interestingly, a low concentration of taurine (0.5 mM) activated glycine receptors, whereas a higher concentration (3 mM) activated both glycine and gamma-aminobutyric acid A (GABA(A)) receptors in PHA neurons. These results suggest that PHA neurons are influenced by taurine and respond via glycine and GABA(A) receptors. 2015 Elsevier Ireland Ltd. All rights reserved.