title: rat pineal gland during day time
design: Three rats were anesthetized and sacrificed under dark conditions (under red light) from 04:00 to 05:00 and were considered the dark group; these rats were named C04, C05 and C06 . Another three rats were anesthetized and sacrificed in bright sunlight from 16:00 to 17:00 and were considered the light group; these rats were named C01, C02 and C03 .