Mechanisms of intrinsically photosensitive retinal ganglion cells regulating learning and memory: a review

pathway, in which norepinephrine released from the LC is involved. Although direct ipRGC projections to the CeA have been validated, the direct modulatory effect of ipRGCs on this pathway remains to be elucidated. In human studies, daytime blue-light exposure and 40 Hz rhythmic blue-light flicker can strengthen visual and auditory working memory and facilitate memory consolidation by activating ipRGC-related pathways, accompanied by prefrontal cortex activation and enhanced hippocampal-thalamic functional connectivity, which reveals promising non-pharmacological potential for memory modulation. Beyond healthy subjects, blue-light intervention also exhibits therapeutic potential for neuropsychiatric disorders. Nevertheless, its clinical translation still requires further standardization of light parameters, development of diurnal and primate animal models, improvement of ipRGC subtype-selective manipulation techniques, as well as long-term stratified clinical studies stratified by age, disease phenotype and memory type, so as to advance the application of intelligent lighting environments and precise phototherapeutic interventions.