Structural and physiological responses to prolonged constant lighting in the cone-rich retina of Arvicanthis ansorgei

►Seven days of constant white light abolish rod and cone shedding rhythms in the diurnal rodent Arvicanthis ansorgei. ►Contrary to one day of constant light, there is significant down-regulation of rod and cone shedding (80 and 50% respectively). ►Seven days of constant light does not provoke any detectable photoreceptor degeneration or outer segment shortening.