Retinitis pigmentosa (RP) is a hereditary retinal disease with progressive loss of rods followed by cones that lead to blindness.How-ever,there has been no effective treatment for this disease.Lycium barbarum polysaccharides (LBPs) are protein complex extracted from wolfberry (also known as Lycium barbarum) and are long known to possess primary beneficial properties in the eyes.Here we investigate whether LBPs rescue the morphology and function of retina in rdl mouse,a fast photoreceptor degenerated animal model,and how LBPs affect the function of retinal ganglion cells (RGCs) during photoreceptor degeneration.LBP or PBS was intraperitoneally injected in rd1 mice every day from postnatal 4 days (P4) to P14,P20,P24 or P28 when photoreceptors totally degenerated.DAPI staining,electroretinogram,visual behavior and multi-electrode-array (MEA) recording were applied to check the structure and function of retina after the treatment.Our study showed that LBP treatment significantly preserved the photore-ceptors,enhanced electroretinogram responses and improved the visual behavior in rd1 mice compared to the non-treated group.Furthermore,by MEA recording from whole-mount retina (Figure 1),we identified the effect of LBP on six dasses of RGCs accord-ing to the property of their light responses,including ON,OFF,ON-OFF sustained and ON,OFF,ON-OFF transient (Della Santina et al.,2013).LBP treatment significantly enhanced the percentage of light-responsive RGCs and increased both their average and the peak light responses during photoreceptor degeneration till P24.The spontaneous spiking,which usually increases during retinal de-generation,was overall inhibited by LBP;while the changes of the light-evoked responses and spontaneous spiking of various types RGCs in treated rd1 mice varied at different stages.Intensity profile tested with a series of increasing flash intensities also showed improved light sensitivity in most RGCs after LBP treatment.Thus LBPs delay the functional decay of retinal ganglion cells during photoreceptor degeneration,which may help to elongate the effective time window for RP treatment.