Observing Age-related Retinal Neurodegeneration in Mouse Models with combined oct and fluorescence imaging

I worked in Dr. Kuo’s biophotonics lab in collaboration with Dr. Tseng’s neuroscience lab to image neurodegeneration in mouse models. Measuring the pattern and rate of retinal neurodegeneration in animal models can help us discover the mechanisms involved in eye diseases such as glaucoma, age related macular degeneration, and diabetic retinopathy, all of which currently have no cure. Understanding such mechanisms can lead to better drug design and targeting for more effective treatments and potential cures.

I tested and progressively refined a homebuilt biomedical imaging system that is the first built for simultaneous optical coherence tomography (OCT) and fluorescence imaging. I used this system to take in vivo cross sectional and en face retinal images of mouse models with fluorescently-labeled retinal ganglion cells. This model allowed me to qualitatively track neurodegeneration in different ages of N-methyl-D-aspartate (NMDA)-treated mice by comparing relative fluorescence in the fluorescent images, as well as by comparing retinal thickness in OCT images.

The results show that neurodegenerative retinal changes present differently as a function of age in NMDA-treated mice, particularly between the ages of 3 and 8 months. Interestingly, these changes can be seen in OCT images but not in fluorescence microscopy at 5 days post-treatment. This suggests that NMDA-induced neurodegeneration leads to retinal morphology transformations prior to detectable molecular changes in the neurons themselves, particularly in older mice. Longitudinal studies are required to follow the progression of these morphologic perturbations, how they can affect the eye or the whole model organism, and how they change as organisms age.

Details

Project duration: Aug. 21, 2016 – Dec. 18, 2017

Weekly hours: 10

Total hours completed: 650

Supervisors: Dr. Anthony Kuo (anthony.kuo@duke.edu) and Dr. Henry Tseng (henry.tseng@duke.edu)