Species-specific Differences in Retinal Aii Cell Connectivity

Olivia Haddadin, Selena Wirthlin, Crystal L. Sigulinsky, James R. Anderson, Daniel P. Emrich, Christopher N. Rapp, Jeebika Dahal, Rebecca L. Pfeiffer, Kevin D Rapp, Jia-Hui Yang, Carl B Watt, Robert E Marc, Bryan W Jones, Bryan W. Jones, Department of Ophthalmology and Visual Sciences, University of Utah John Moran Eye Center, 65 Mario Capecchi Drive Salt Lake City, Utah 84132

Preliminary research has shown differences between retinal pathways in rabbits and mice, indicating signal flow may differ between species. Animal models are commonly used in an attempt to learn more about human biology. As a result, identifying differences between different species’ visual systems can help researchers determine what model is best and how data may be best interpreted. The Aii cell is an interneuron in the mammal retina that allows the night vision pathway to use structures of the day vision pathway. During the day, cone bipolar cells collect cone photoreceptor information and transfer signals to cells that connect to the brain. During the night, however, rod bipolar cells collect information from rod photoreceptors and transfer signals to Aii cells. Aii cells communicate through making various types of synapses with different partners. I find these synapses and identify their type and partner cells through retinal connectomics, which can then be compared across species. Retinal Connectomes 1 and 2 (RC1, RC2) are built by automated transmission electron microscopy at 2.18 nm/pixel resolution. Both are 0.25 mm diameter volumes of retina. RC1 is from a 13 month old female rabbit and RC2 is from a 5 month old female mouse. Aii amacrine cells and their partners were annotated using the Viking application before being explored with 3D rendering and graph visualization of connectivity. Mouse and rabbit Aii cells differ in morphology as well as frequency and location of their synapses, suggesting a difference in ON versus OFF pathway participation. I am identifying the difference in signal output flow to ON vs OFF pathways in mouse versus rabbit, which can then be used to make comparisons to Aii cells in a non-human primate. 

Additional Abstract Information

Presenter: Olivia Haddadin

Institution: University of Utah

Type: Poster

Subject: Biology

Status: Approved

Time and Location

Session: Poster 3
Date/Time: Mon 4:30pm-5:30pm
Session Number: 3134