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Institute of Neuroscience Faculty

William Roberts
William Roberts

Professor, Department of Biology
B.A., 1971, Harvard;
Ph.D 1979, University of California, San Diego

Research Interests
Signal processing in sensory systems, synaptic transmission, calcium signaling

roberts@uoneuro.uoregon.edu

 

The frog sacculus is an auditory and seismic detector that is exquisitely sensitive to vibrations at frequencies of 25-75 Hz. Sensitivity to vibrations within a particular frequency band (frequency tuning) is a common feature of auditory systems, and is known to involve a variety of sophisticated mechanical and electrical processes. In many auditory organs, including the frog sacculus, it has been proposed that frequency tuning is accomplished primarily by the electrical properties of the sensory receptors (hair cells) themselves. This type of intrinsic frequency tuning in receptor cells is known as "electrical resonance". We are interested in electrical resonance, synaptic transmission, and related specializations of hair cells because of their importance in auditory processing, and more generally as a model system in which to study the cellular physiology of fast signal processing in the nervous system.

Electrical resonance in hair cells involves an interaction between two or more types of ion channels (voltage-gated calcium channels and one or more classes of potassium channels) and the cell's electrical capacitance. We are currently investigating the biophysical properties of these ion channels to determine the basis for electrical resonance in the frog sacculus, and to test whether electrical resonance is sufficient by itself to account for tuning in this organ. We are particularly interested in the role of calcium as a rapid, short-range intracellular messenger, including how the calcium signal is shaped by the presence of high concentrations of diffusible calcium-binding proteins in the cytoplasm. This calcium signal is important for both electrical resonance and for synaptic transmission.

We are also investigating the physiology and anatomy of the hair cell's synapses onto afferent axons. These synapses are specialized for chemical transmission without action potentials. They closely resemble the "ribbon synapses" of photoreceptors and other cells in the retina. We are particularly interested in understanding how the unique anatomical features of these synapses may contribute to their physiological properties.

Representative Publications

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University of Oregon

Last Updated 9/19/2014 -