Timothy Kraft, Ph.D.Timothy Kraft, Ph.D., professor and interim associate dean for Research in the School of Optometry at the University of Alabama at Birmingham, has received a grant renewal of $464,046 from the National Institutes of Health. Cone photoreceptors are light-sensitive neurons in the retinas of eyes. Unlike rod photoreceptors — cells that are specialized for night vision — cone cells function better in bright light. The grant continues research about these cone photoreceptors, with a plan to quantitatively define how visual signals are generated by the nervous system.
The primary aim of this grant is to produce a comprehensive characterization of cone photoreceptor physiology in cone-dominated animals, including primates. This data will be used to develop a model of response properties that scientists may use to describe the limits and boundaries of what in vivo versus in vitro experiments can learn about the retina.
“These experiments are at the cutting edge of experimental technology,” Kraft said. “They utilize a two-photon laser and its controller for femto-second pulses (being designed in Dr. Sincich’s lab) and will be applied in vivo to target a single cone for stimulation using adaptive optics and used in vitro, where I will record directly from single cone photoreceptors.”
Additionally, Kraft wants to detail how a novel form of cone activation can be used to improve spatial stimulation of cones. He explains that, to predict where and how visual signals are generated by the nervous system, we must understand how the cone photoreceptors behave in different lighting conditions. Assumptions scientists have made for decades about photoreceptor responses must be directly tested. For instance, do the observations made from cells in a dish also match the behavior of cells in the living eye? Will the photoreceptors of salamanders and turtles that are used in testing be a reasonable stand-in for primate and human tissue?
The grant has been renewed for the second time, and the total amount of money that will be awarded is $1.77 million over four years. Lawrence Sincich, Ph.D., an associate professor in the School of Optometry, is the co-principal investigator of the project.