Celebration of Scholarship and Creative Activity 2023
The 13-Lined Ground Squirrel (13-LGS) visual system is remarkably similar to that of humans, making it a useful animal model for blinding diseases and prompting research to create 13-LGS mutants with human hereditary retinal degenerations. While humans can report visual function by using an eye chart, rodents must be tested by using the Optomotor Reflex (OMR) Device. The OMR is a head movement tracking device equipped with moving stripes and a camera. The user controls the size and speed of the stripes: thick-slow moving stripes are like the large letters on the human eye chart, whereas thin-fast moving stripes are like the smaller letters. When the animal can see the stripes move, its head will move reflexively to track them. When the animal can no longer see the stripe movement, the corresponding head movements cease. The OMR requires the unrestrained animal subject to always voluntarily remain on the platform in camera focus. The OMR has never been attempted with 13-LGS, so this project addressed the species’ response to the device and how positive reward conditioning might facilitate its successful use. The training scheme used and the time frame over which it occurred gave only one clear positive (a male) among the 8 juvenile littermate subjects, although a female also showed intermittent improvement to a lesser extent. These data suggest that, under the conditions employed, we expect significant inter-individual variation in how well positive reward conditioning works for the task of remaining on the raised platform of an OMR device.