Department of Neuroscience
Professor and Chair
College of Medicine
Department of Neuroscience, Oral Biology
Research Interests: Dr. Herness is interested in sensory neuroscience. His research includes investigation of signal transduction mechanisms in mammalian taste receptor cells. Areas of focus include the roles of second messenger signaling cascades, neuropeptides and neurotransmitters.
Current Research: Taste stimuli — often characterized as bitter, sweet, salty and sour — utilize differing mechanisms to electrically excite the taste-receptor cell. This cell then fires an action potential causing a still unknown transmitter to be released onto an afferent nerve fiber. The afferent fiber then relays this information to the central nervous system. Dr. Herness' current research focuses on the intracellular transduction mechanisms in the taste receptor cells that somehow couple receptor molecules to ion channels.
Using the patch clamp recording technique, Dr. Herness' team has characterized a number of voltage-dependent ion channels in dissociated taste receptor cells from the rat tongue. They have investigated how these currents are modulated by the cyclic AMP and the inositol trisphosphate second messenger systems. They have also established that ion channels in taste cells are modulated by neurotransmitters (norepinephrine and serotonin), which affect the transduction mechanisms for taste stimuli. Additionally, they have recently identified the neuropeptide cholecystokinin within some taste cells within the taste bud. Researchers have demonstrated that its release affects the electrical excitability of taste cells. They are pursuing many of these observations with modern molecular techniques.
Molecular: In situ hybridization, Western blot analysis and RT-PC
Electrophysiological: Patch-clamp recording on dissociated cells (whole cell and single channel)
Other: Calcium imaging (Fura-2)
Degree: The Florida State University
Postdoctoral: The Rockefeller University, Dr. Carl Pfaffmann