(full paper is archived in the Miller Library)
Title: Calcium imaging of adult Zebrafish
(Danio rerio) optic tectum reveals dendritic
activity
Student Author(s): Parente, Victoria
To, Jennifer
Faculty Advisor(s): Thompson, Stuart
Pages: 16
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.