낮밤의 주기에 따른 뇌중 serotonin 함량의 변화에 대한 연구

A Study of Diurnal Variation in Brain Serotonin Concentration

  Sprague-Dawley male rats were used to investigate daily rhythms in brain concentration of serotonin. Considerable information is available concerning affecting plasma levels of the neutral amino acids, particularly their changes as a function of time of day, or after consumption of meals of varying composition. Moreover, abundant evidence has accumulated that these plasma changes can affect the brain. The diurnal variations of the plasma amino acids, especially, the large neutral amino acids(LNAA), might influence the brain levels of certain amino acids and their products including neurotransmitters. The brain concentrations of serotonin and its chief metabolite, 5-hydroxyindoleacetic acid(5-HIAA) showed a peak at the late light period and at the beginning of dark. Also, a plateau was attained at the late dark. Therefore, the present study suggests the possibility that protein and carbohydrate consumptions also have the daily rhythms.