Shing-Yan Chiu

 

 

Voltage-and Ligand-Gated Channels in Neural-Glia Interactions

E-mail: chiu@physiology.wisc.edu

Research Strength: Molecular Neuroscience

Potassium channels are crucial modulators of excitability in normal and pathological nerves. In the mammals, multiple K channel gene families encode different geneproducts exhibiting diversity in kinetics, cellular localizations, and responsiveness to second messengers. The goal of this laboratory in collaboration with the lab of A. Messing is to elucidate the in vivo functions of K channels using a combination of electrophysiology and transgenics/gene knockout techniques. Our current focus is on Shaker Channels (Kv1.1, Kv1.2, Kv1.5) and auxiliary K channel subunits (Kvbeta1/Kvbeta2). Viable global knockout mice of these channel genes have been produced and are now under physiological and molecular analysis. Currently, two broad questions are being addressed. First, what is the functional impact of deleting these K channels in normal and demyelinated nerves, particularly at axonal branch points? Second, what are the roles of Kvbeta2 subunits in oxidative stress and neurodegeneration in mice? Physiological techniques including patch-clamping and calcium imaging. Molecular techniques include transgenics, global and conditional gene knockouts.

Selected Publications:

• Zhou, L., and S.Y. Chiu. 2001. A computer model for action potential propagation through branch point in myelinated nerves. J. Neurophysiol. 85: 197-210. [PDF]
• Wrabetz, L., M.L. Feltri, A. Quattrini, D. Imperiale, S. Previtali, M. D'Antonio, R. Martini, X. Yin, B.D. Trapp, L. Zhou, S.Y. Chiu, and A. Messing. 2000. Poglycoprotein overexpression causes congenital hypomyelination of peripheral nerves. J. Cell Biol. 148: 1021-1034.
• Smart, S.L., V. Lopantsev, C.L. Zhang, C.A. Robbins, H. Wang, S.Y. Chiu, P.A. Schwartzkroin, A. Messing, and B.L. Tempel. 1998. Deletion of the Kv1.1 potassium channel causes epilepsy in mice. Neuron 20: 809-819. [PDF]
• Zhou, L., C.L. Zhang, A. Messing and S.Y. Chiu. 1998. Temperature-sensitive neuromuscular transmission in Kv1.1 null mice: role of potassium channels under the myelin sheath in young nerves. J. Neurosci. 18: 7200-7215. [PDF]
• Zhuo, L., B. Sun, C.L. Zhang, A. Fine, S.Y. Chiu, and A. Messing. 1997. Live astrocytes visualized by green fluorescent protein in transgenic mice. Dev. Biol. 187: 36-42.