Influence of white-light-emitting diodes on primary visual cortex layer 5 pyramidal neurons (V1L5PNs) and remodeling by blue-light-blocking lenses

Studies have explored the consequences of excessive exposure to white-light-emitting diodes (LEDs) in the retina. Hence, we aimed to assess the implications of such exposure on structural alterations of the visual cortex, learning and memory, and amelioration by blue-light-blocking lenses (BBLs). Eight-week-old Wistar rats (n = 24) were used for the experiment and divided into four groups (n = 6 in each group) as control, white LED light exposure (LE), BBL Crizal Prevencia-1 (CP), and DuraVision Blue-2 (DB). Animals in the exposure group were exposed to white LED directly for 28 days (12:12-h light/dark cycle), whereas animals in the BBL groups were exposed to similar light with BBLs attached to the LEDs. Post-exposure, a Morris water maze was performed for memory retention, followed by structural analysis of layer 5 pyramidal neurons in the visual cortex. We observed a significant difference (P < 0.001) in the functional test on day 1 and day 2 of training in the LE group. Structural analysis of Golgi-Cox-stained visual cortex layer 5 pyramidal neurons showed significant alterations in the apical and basal branching points (p < 0.001) and basal intersection points (p < 0.001) in the LE group. Post hoc analysis revealed significant changes between (p < 0.001) LE and CP and (p < 0.001) CP and DB groups. Constant and cumulative exposure to white LEDs presented with structural and functional alterations in the visual cortex, which are partly remodeled by BBLs.