[The effect of epiphysectomy on the dynamics of circadian mobility in rats].

In the paper were studied the rats' individual circadian locomotor activity rhythm patterns and their day and night time sensitivity to hexobarbital sodium and diazepam. Pinealectomy without altering the rhythm patterns significantly increased their amplitude and enhanced the hypnotic effect of hexobarbital both in the daytime and at night and that of diazepam only in the daytime. The animal rhythm patterns and the circadian variations of their sensitivity to the hypnotic drugs were suggested to depend on the individual variations of the pineal activity.