title: New Developments in Murine Imaging for Assessing Photoreceptor Degeneration In Vivo.
abstract: Optical Coherence Tomography (OCT) is a powerful clinical tool that measures near infrared light backscattered from the eye and other tissues. OCT is used for assessing changes in retinal structure, including layer thicknesses, detachments and the presence of drusen in patient populations. Our custom-built OCT system for the mouse eye quantitatively images all layers of the neural retinal, the RPE, Bruchs' membrane and the choroid. Longitudinal assessment of the same retinal region reveals that the relative intensities of retinal layers are highly stable in healthy tissue, but show progressive increases in intensity in a model of retinal degeneration. The observed changes in OCT signal have been correlated with ultrastructural disruptions that were most dramatic in the inner segments and nuclei of the rods. These early changes in photoreceptor structure coincided with activation of retinal microglia, which migrated vertically from the inner to the outer retina to phagocytose photoreceptor cell bodies (Levine et al., Vis Res 102:71-79, 2014). We conclude that quantitative analysis of OCT light scattering signals may be a useful tool for early detection and subcellular localization of cell stress prior to cell death, and for assessing the progression of degenerative disease over time. Future efforts to develop sensitive approaches for monitoring microglial dynamics in vivo may likewise elucidate earlier signs of cellular stress during retinal degeneration.
authors.affiliation: Department of Ophthalmology and Vision Science, University of California Davis, 3301B Tupper Hall, 95616, Davis, CA, USA. meburns@ucdavis.edu.|Center for Neuroscience, University of California Davis, 1544 Newton Court, 95618, Davis, CA, USA. meburns@ucdavis.edu.|Cell Biology and Human Anatomy, University of California Davis, 3307 Tupper Hall, 95616, Davis, CA, USA. meburns@ucdavis.edu.
authors.forename: Marie E
authors.initials: ME
authors.lastname: Burns
authors.affiliation: Cell Biology and Human Anatomy, University of California Davis, 3307 Tupper Hall, 95616, Davis, CA, USA. elevine@ucdavis.edu.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Levine
authors.affiliation: Center for Neuroscience, University of California Davis, 1544 Newton Court, 95618, Davis, CA, USA. ebmiller@ucdavis.edu.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Miller
authors.affiliation: Cell Biology and Human Anatomy, University of California Davis, 3307 Tupper Hall, 95616, Davis, CA, USA. azam@ucdavis.edu.
authors.forename: Azhar
authors.initials: A
authors.lastname: Zam
authors.affiliation: Cell Biology and Human Anatomy, University of California Davis, 3307 Tupper Hall, 95616, Davis, CA, USA. pfzhang@ucdavis.edu.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology and Vision Science, University of California Davis, 3301B Tupper Hall, 95616, Davis, CA, USA. rjzawadzki@ucdavis.edu.|Cell Biology and Human Anatomy, University of California Davis, 3307 Tupper Hall, 95616, Davis, CA, USA. rjzawadzki@ucdavis.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Zawadzki
authors.affiliation: Department of Ophthalmology and Vision Science, University of California Davis, 3301B Tupper Hall, 95616, Davis, CA, USA. enpugh@ucdavis.edu.|Cell Biology and Human Anatomy, University of California Davis, 3307 Tupper Hall, 95616, Davis, CA, USA. enpugh@ucdavis.edu.
authors.forename: Edward N
authors.initials: EN
authors.lastname: Pugh
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D017628:Microglia / Q000378:metabolism / Q000473:pathology; D015203:Reproducibility of Results; D012160:Retina / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D012162:Retinal Degeneration / Q000175:diagnosis* / Q000235:genetics; D055211:Retinal Photoreceptor Cell Inner Segment / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D049452:Green Fluorescent Proteins
keywords: Arrestin-1; Imaging; Microglia; Mouse; Optical coherence tomography (OCT); Photoreceptor; Phototransduction; Rod; Scanning laser ophthalmoscopy (SLO)