Dr. Harold Zakon
Office: PAT 328
Lab: PAT 329
phone: (512) 471-0194
Harold Zakon received his Ph.D. in Neurobiology & Behavior from Cornell University in 1981. He did postdoctoral research at the Scripps Institution of Oceanography, which is part of the University of California at San Diego from 1981-1983. He joined the faculty of the former Zoology Department at the University of Texas in 1983. He has been Chairman of the Section of Neurobiology since it was founded in 1999. He has served on grant review panels at the NIH, and currently serves on editorial boards of a number of scientific journals and advisory boards of scientific societies. He has won awards for his research, such as a Research Career Development Award from the NIH, as well as for teaching excellence at the University of Texas. He was a director and faculty member of the “Neural Systems and Behavior” summer course at the Marine Biological Laboratory in Woods Hole, Massachusetts from 1995-2000, and is the Chairman of the “Gordon Research Conference in Neuroethology” at Oxford University that will meet in the summer of 2002. He also holds a position as Adjunct Scientist at the Marine Biological Laboratory.
We study a number of questions in my laboratory using weakly electric fish as our model organism. These fish live in murky waters and are nocturnally active. They generate weak electric fields around themselves from a specialized electric organ that is derived from muscle cells, and sense these electric fields, with specialized sensory receptors. They sense the distortions caused in the own electric fields to locate nearby objects, and use their electric fields to broadcast electric signals other fish.
The electric organ discharge varies across species, is different in the two sexes, and varies in each individual. It is influenced by social factors and hormones, and may show circadian variations as well. These discharges can be easily recorded in freely behaving animals. The circuitry for generating them is simple and many of the cells are accessible for electrophysiological analysis. Thus, we can study dynamic biophysical events in excitable membranes from the level of freely behaving animals to the level of the ion channels themselves.
Our main focus has been the regulation of sodium and potassium currents in the electric organ by sex steroid hormones (which accounts for sex differences in the discharge) and phosphorylation (which accounts for circadian variations). A major new emphasis of the laboratory has been the molecular cloning of these ion channels to understand their regulation on the molecular level, and their evolution.
Other projects include studies of the modulation of the electric discharge pattern by NMDA receptors in the brain; behavioral studies of communication and social interaction in electric fish; understanding the molecular and developmental mechanisms whereby a differentiated muscle cell has evolved into a novel type of cell--an electric organ cell, a question first posed by Charles Darwin in the “Origin of Species.”