Fig. 5

Microglial depletion reduces contrast sensitivity and ERG c-wave. A Contrast sensitivity function was measured using vertically oriented sinusoidal gratings of different contrast and spatial frequency (cycles per degree). Example of the OMR setup at 0.133cyc/deg to measure contrast sensitivity at full (99.73%), at 34% and at 10% contrast. Mice have worse vision when higher contrast is required to track the stripes. B Example of the OMR setup to measure visual acuity with increasing cycles per degree (0.056, 0.167 and 0.367) at maximum contrast. Significant reduction of visual acuity was measured between the young and old mice, but microglia depletion did not further affect the visual acuity measured at maximum contrast (99.73%). C Microglia-depleted mice showed reduced contrast sensitivity (higher contrast requirements corresponds to reduces contrast sensitivity and reduced vision) and D quantification revealed statistical significance at mid-range spatial frequencies. E Significant reduction of a-wave (F) and b-wave amplitudes was recorded between young and aged mice, but microglial depletion in older mice did not affect the a-wave and b-wave amplitudes. G Maximum c-wave amplitude was significantly reduced in aged mice compared to young and microglia depleted mice showed further reduction of c-wave amplitudes compared to the control mice. H Representative c-wave ERG comparing young (3-months) control and depletion diet. n = 8 mice per group, 2-way ANOVA, Šídák's multiple comparisons test. **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001; ns, not significant