EFFECTS OF SAIKO-KA-RYUKOTSU-BOREI-TO ON IRRITABLE CHARACTERISTICS INEL MICE

In the present study, we attempted to characterize the circadian rhyth m of locomotor activity of El mice and to examine the duration of sodi um pentobarbital-induced sleep during the light and dark periods. The effect of Saiko-ka-ryukotsu-borei-to, a representative Kampo medicine used for treating insomnia, was studied on the locomotor activity and on the duration of sodium pentobarbital-induced sleep in El mice. The spontaneous locomotor activity of El mice during the dark period was n ot so different from that of ddY mice, whereas the activity during the light period was significantly higher in the El mice, and the duratio n of sodium pentobarbital-induced sleep of El mice was very short duri ng the light period, nearly equal to that during the dark period. The administration of Saiko-ka-ryukotsu-borei-to caused marked reduction i n the locomotor activity during the light period and dose-dependent pr olongation in the duration of sodium pentobarbital-induced sleep time during the light period, but that during the dark period was unaffecte d. These findings suggest that the El mouse is a model with a tendency to be easily excitable during the light period compared to ddY mice. Furthermore, it was confirmed that Saiko-ka-ryukotsu-borei-to reduced the excitation in El mice and might be useful against sleep disorders due to excitation.