Objective: To investigate the effects of targeted ablation of melanopsin-containing retinal ganglion cells (mcRGCs) on non-image-forming function in rd mice (C3H/HeJ).
Methods: Different doses (100ng/ul, 200ng/ul, 400ng/ul) of immunotoxin melanopsin-SAP were intravitreally injected into the eyes in 3 groups of rd mice respectively, the density of mcRGCs was examined on flat mount retina. The wheel-running system was used to evaluate the non-image-forming visual function of PBS control group, 100ng/ul group and 200ng/ul group rd mice.
Results: The survival rate of mcRGCs in the 100ng/ul, 200ng/ul and 400ng/ul group was 65% ± 1.2%, 40% ± 2.8% and 40% ± 3.1% respectively. The results of free-running records system showed that: in C3H/HeJ mice, PBS control group, it took 6 days to complete the synchronization with the lighting conditions, in the 100ng/ul group, it took than 10 days to complete the synchronization with the light conditions; and in the 200ng/ul group, the mice lost the function of synchronization with the lighting conditions.
Conclusion: Intravitreal injection of immunotoxin melanopsin-SAP can target kill the mcRGCs. In rd mice, without the function of rod and con, the loss of mcRGCs can cause the non-image-forming function change. It suggests that the intact functional mcRGCs were essential to regulate non-image-forming visual functions.