title: Diurnal and seasonal variations of glycogen content in the rat brain.
abstract: The effect of seasonal and diurnal variations on glycogen content in the brain was investigated in 3-month old Wistar rats. In the first experimental series, the glycogen content in the brain was determined every 2-months, throughout a whole year. In each experiment, the material was taken at the same time of a day. The results indicated that the brain glycogen content did not change significantly, during the periods of a year examined. In the second series of experiments, the glycogen content in the rat brain was assayed every 3 hours, during a 24-hour-period. A low content of glycogen in the rat brain was found during the night, with a pronounced decrease of this value between 9.00 p.m. and midnight. A possible relationship between the diurnal changes in the brain glycogen content and catecholamine metabolism in the central nervous system is discussed.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry; D002395:Catecholamines / Q000378:metabolism; D002940:Circadian Rhythm; D005260:Female; D006003:Glycogen / Q000032:analysis*; D008297:Male; D010507:Periodicity; D051381:Rats; D012621:Seasons
chemical_list: D002395:Catecholamines; D006003:Glycogen