Modulation of extracellular neurotransmitter levels in the nucleus accumbens by a taurine uptake inhibitor

Using in vivo microdialysis, we examined the effect of local perfusion of t he taurine uptake inhibitor guanidinoethyl sulfonate on extracellular level s of various neurotransmitters in the rat nucleus accumbens. Guanidinoethyl sulfonate (500 muM-50 mM) produced a concentration-dependent increase in e xtracellular taurine levels. While 500 muM and 5 mM concentrations of guani dinoethyl sulfonate were largely without effect, 50 mM guanidinoethyl sulfo nate produced a significant decrease in extracellular levels of aspartate, glutamate and glycine, with no effect on extracellular dopamine levels. The se results indicate that guanidinoethyl sulfonate can modulate extracellula r amino acid levels in the nucleus accumbens. (C) 2000 Elsevier Science B.V . All rights reserved.