Magnetic resonance imaging investigations reveal that PM2.5 exposure triggers visual dysfunction in mice.

Objectives To investigate how PM2.5 exposure affects the microstructure, metabolites or functions of the visual system. Methods C57BL/6J mice were randomly assigned to groups exposed to the filtered air (the control group) or the concentrated ambient PM2.5 (the PM2.5 group). Visual evoked potentials (VEP), electroretinograms (ERG), diffusion tensor imaging (DTI), proton magnetic resonance spectroscopy (1H-MRS) and resting-state functional MRI (rsfMRI) were performed. Parameters were obtained and compared between the two groups, including latencies and amplitudes of the P1 wave, N1 wave and P2 wave from VEP, latencies and amplitudes of the a wave and b wave from ERG, fractional anisotropy (FA), mean diffusion (MD), axial diffusivity (AD) and radial diffusivity (RD) from DTI, visual cortex (VC) metabolites from 1H-MRS, and regional homogeneity (ReHo) from rsfMRI. Results Compared with the values of the control group, the PM2.5 group showed a prolonged N1 latency (43.11 ± 7.94 ms vs. 38.75 ± 4.60 ms) and lowered P1 amplitude (5.62 ± 4.38 μV vs. 8.56 ± 5.92 μV) on VEP (all p Conclusions This study revealed that PM2.5 exposure triggered visual dysfunction, and altered microstructure, metabolite and function in the retina and visual brain areas along the visual system.