Department of Chemistry
R Wightman

Mark Wightman

W.R. Kenan, Jr. Professor of Chemistry
rmw@unc.edu
919-962-1472
919-962-2388 (fax)
Caudill 339

 

Research Interests

Ultramicroelectrodes, Electrochemistry, Neurochemistry

Professional Background

University of North Carolina at Chapel Hill Ph.D. (1974). Postdoctoral Research Associate, University of Kansas (1974-1976). Faculty member, Indiana University (1976-1989); National Institutes of Health Research Career Development Award (1979-1983); Alfred P. Sloan Fellowship (1981-1983); Jacob Javits Neuroscience Investigator Award, NIH (1989); Chemical Instrumentation Award, Analytical Chemistry Division of ACS (1994); David Graham Award, Physical Electrochemistry Division of the Electrochemical Society (1995); Charles N. Reilley Award, Society for Electroanalytical Chemistry (1996); Simon Guggenheim Research Fellowship (1996); Pittsburgh Conference Analytical Chemistry Award (1997); Society for Electroanalytical Chemistry President (1997-1999), Erskine College Academic Hall of Fame (1999); Electrochemistry Award, Analytical Division of ACS (2001); Fellow, AAAS (2002-present); Faraday Medal, Electrochemistry Group, Royal Society of Chemistry (2005); R. N. Adams Award in Bioanalytical Chemistry, Pittsburgh Conference (2006); ACS Analytical Chemistry Award (2008); Sir Bernard Katz Award for Excellence in Research on Exocytosis and Endocytosis, Biophysical Society (2010); The Herty Medal, Georgia Section of the American Chemical Society, (2011)

Research Synopsis

Our research interests center around microelectrodes and their use to probe complex chemical and biochemical phenomena. Microelectrodes are chemical sensors that have micron or smaller dimensions. Their small size enables measurements in unusual environments. We have capitalized on this to make measurements at single biological cells and in intact brain tissue. The microelectrodes have enabled us to characterize a number of unique events. At single cells, we have been able to characterize single exocytotic events in which the contents of a single vesicle are released into the surrounding environment. In intact brain tissue we have been able to monitor neurotransmitters in the extracellular space. Our investigations show that the lifetime of these chemical messengers in the vicinity of their receptors is dictated by the balance between exocytotic release and their removal by uptake, a transporter-mediated process in which neurotransmitters are repackaged back into neurons. An important application of this work is the measurement of these neurochemical changes as they dictate an organism's behavior.

These chemical measurements put high requirements on the quality of the measured data. We need to use electrochemistry to detect specific substances, characterize their concentrations, and follow their dynamic changes with subsecond time resolution. Through the use of sophisticated, rigorous, analytical techniques, these goals are being accomplished.