Age-related differences in retinal function and structure in C57BL/6J and Thy1-YFPh mice

Age-related neuronal adaptations are known to help maintain function. This study aims to examine gross agerelated in vivo retinal functional adaptations (using electroretinography) in young and middle aged C57BL/6J and Thy1-YFPh mice and to relate this to in vivo retinal structure (using optical coherence tomography). Electroretinography responses were generally larger in Thy1-YFPh mice than in C57BL/6J mice, with similar in vivo retinal layer thicknesses except for longer inner/outer photoreceptor segment in Thy1-YFPh mice. Relative to 3month-old mice, 12-month-old mice showed reduced photoreceptor (C57BL/6J 84.0 +/- 2.5 %; Thy1-YFPh 80.2 +/- 5.2 %) and bipolar cell (C57BL/6J 75.6 +/- 2.3 %; Thy1-YFPh 68.1 +/- 5.5 %) function. There was relative preservation of ganglion cell function (C57BL/6J 79.7 +/- 3.7 %; Thy1-YFPh 91.7 +/- 5.0 %) with age, which was associated with increased b-wave (bipolar cell) sensitivities to light. Ganglion cell function was correlated with both b-wave amplitude and sensitivity. This study shows that there are normal age-related adaptations to preserve functional output. Different mouse strains may have varied age-related adaptation capacity and should be taken into consideration when examining age-related susceptibility to injury.