(full paper is archived in the Miller Library)
Title: Calcium imaging of adult Zebrafish
(Danio rerio) optic tectum reveals dendritic
Student Author(s): Parente, Victoria
Faculty Advisor(s): Thompson, Stuart
Location: Final Papers Biology 176H
Date: June 2006
Abstract: Zebrafish has long been a model organism for studying the visual system. They have a similar visual system as higher vertebrates but lack a visual cortex. Instead, higher order visual processing occurs in the optic tectum. Previous studies of the zebrafish visual system have used mainly electrophysiological techniques to record wide field responses. We have developed a new technique for perfusing and calcium imaging of live adult zebrafish. This technique allows for simultaneously recording of response in large neuronal populations and activity in neuronal processes as small as 2-5 um. Zebrafish was immersed in and perfused over the gills with physiological 75% Hank's solution in a custom-built perfusion system. Optic tectum of zebrafish was exposed in a dissection and microinjected with fluorescent calcium indicator Fluo3. Confocal microscope was used to image calcium activity in dendrites in the optic tectum receiving input from the retina. A train of light flashes given in five-second intervals was used as stimulus. Time series of responses were recorded at two frames per second. Graphical analysis reveals that dendritic responses to stimuli showed different activity levels and oscillation patterns compared with control, but responses were not time-locked to stimuli. Responses varied between dendrites, with both excitation and inhibition evident. Neighboring dendrites showed a higher correlation in activity, suggesting synchronization of neuronal populations in response to light stimuli.