This investigation will determine the modulatory actions of zinc in the vertebrate retina, where the presence of this important trace element has been established. The goals of this project will be achieved using a multidisciplinary approach involving measurement of changes to electrophysiological responses which result from application of appropriate pharmacological agents and development of quantitative measurements of zinc release from retinal cells. The results will reveal mechanisms by which zinc released from photoreceptor terminals feeds-back to reduce the calcium entry involved in glutamate release, thereby reducing unnecessary glutamate release in the dark. Results will also provide increased understanding of the ways in which zinc affects hemi-channels, the constituents of gap junctions between retinal neurons. These affects will influence interactions involved in contrast sensitivity and/or the spread of cell death from injured neurons. Knowledge of these mechanisms will be greatly enhance our understanding of the neural mechanisms mediating early events of visual processing in the retina as well as protection from glutamate cytotoxicity in the retina and elsewhere in the central nervous system. While advancing discovery and understanding in the stated scientific problems, the project will have broader impacts through its role in promoting teaching, training and learning in an environment that offers significant educational opportunities to underrepresented minority students.
