Activation of Glycine and Extrasynaptic GABAA Receptors by Taurine on the Substantia Gelatinosa Neurons of the Trigeminal Subnucleus Caudalis. (28th November 2013)

• Record Type: Journal Article
• Authors: Nguyen, Thi Thanh Hoang; Bhattarai, Janardhan Prasad; Park, Soo Joung; Han, Seong Kyu
• Other Names: Youn Dong-ho Academic Editor.
• Is Part Of: Neural plasticity. Volume 2013(2013)
• Publication Date: 2013-11-28
• Subjects: Neuroplasticity -- Periodicals; 612.82
• DOI: 10.1155/2013/740581
• Languages: English
• ISSNs: 2090-5904

Abstract

Abstract : The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) has been known for the processing and transmission of orofacial nociceptive information. Taurine, one of the most plentiful free amino-acids in humans, has proved to be involved in pain modulation. In this study, using whole-cell patch clamp technique, we investigated the direct membrane effects of taurine and the action mechanism behind taurine-mediated responses on the SG neurons of the Vc. Taurine showed non-desensitizing and repeatable membrane depolarizations and inward currents which remained in the presence of amino-acid receptors blocking cocktail (AARBC) with tetrodotoxin, indicating that taurine acts directly on the postsynaptic SG neurons. Further, application of taurine at different doses (10 μ M to 3 mM) showed a concentration dependent depolarizations and inward currents with the EC50 of 84.3 μ M and 723 μ M, respectively. Taurine-mediated responses were partially blocked by picrotoxin (50 μ M) and almost completely blocked by strychnine (2 μ M), suggesting that taurine-mediated responses are via glycine receptor (GlyR) activation. In addition, taurine (1 mM) activated extrasynaptic GABAA receptor (GABAA R)-mediated currents. Taken together, our results indicate that taurine can be a target molecule for orofacial pain modulation through the activation of GlyRs and/or extrasynaptic GABAA Rs on the SG neurons.