Dr. William J. Betz, Professor and Chair of the Department of Physiology & Biophysics at the University of Colorado, will present the 20th annual Einar Hille Memorial Lecture in Neurosciences, sponsored by the Department of Physiology and Biophysics. He will speak on “The release of transmitter and the recycling of synaptic vesicles at the vertebrate neuromuscular junction” on Wednesday, March 31 at 4:00 p.m. in room T-739 of the Health Sciences Building. The lecture is free and open to everyone.
Problems at the neuromuscular junction underlie a number of diseases, including myasthenia gravis.
Since the early 1990′s, Betz has pioneered the use of fluorescent FM dyes that have proven extremely useful for the optical reporting of synaptic vesicle cycling at the neuromuscular junction and small central nervous system synapses. When synaptic vesicles exocytose — a sort of cellular volcanic eruption– and release their neurotransmitter contents in the presence of extracellular FM dye, the dye enters the vesicles and is taken up into the neuron upon endocytosis, in which a vesicle folds inward to engulf and ingest materials.
When the extracellular dye is washed away from the outside of the cells, the labeled intracellular vesicles remain as the only fluorescent signal. When a dye-filled vesicle recycles and fuses again with the plasma membrane, its dye is spilled along with its neurotransmitter contents. The spill leads to a decrease in the fluorescent signal. By following the uptake and loss of FM dye signal, the activity of many synapses can be simultaneously monitored using relatively non-invasive optical techniques.
Betz’s talk will review previous studies on the neuromuscular junction performed by many different laboratories, and will also discuss recent work from his own lab aimed at mapping the spatial profile of exocytosis in living nerve terminals using both genetically-encoded (synaptopHluorin) and exogenous (FM1-43) fluorophores.
The Einar Hille Memorial Lecture in Neurosciences was established by Kirsti Hille in honor of her late husband. Hille was a professor of Mathematics at Yale University and a member of the National Academy of Sciences. Dr. Bertil Hille, son of Einar and Kirsti Hille, is the Wayne E. Crill Endowed Professor of Physiology and Biophysics at the UW.