Figure 1.
The mice were given CE-2 (CLEA Rodent Diet CE-2 for breeding) standard pellet chow. Tap water was used for drinking and was given ad libitum. Before the start of the experiment, mice were fed powder chow during a week-long acclimatization period in order to measure the feed intake in normal mice. In the first period, we measured food and water intake, and intake time using K2CABIN (Figure 2). In the second period, we measured the amount and rhythm of movement behavior using KUROBOX (Figure 2). In the third period, mice were fasted for 3 days, only drinking water was given ad libitum.
Figure 2.
K2CABIN system and KUROBOX system.
(A) K2CABIN system used to measure eating patterns and KUROBOX system used to measure movement patterns of behavior. (B),(C) KUROBOX; This measures the movement of mice by infrared sensors. We calculated the distance travelled by the mouse, the speed and the movement angle over time.
Figure 3.
Food and water intake of mice in the first period under ad libitum.
(A) An example of the food and water intake pattern in a mouse. (B) Average food intake. Values are Mean ± S.D. (n = 10). (C) Average water intake. Values are Mean ± S.D. (n = 10).
Figure 4.
Movement behavioral patterns and running distance of mice in the second period given ad libitum intake of food and water.
(A) An example of the movement behavioral pattern of a mouse in the second period. (B) Running distance in a dark and light phase in the second period. Values are Mean ± S.D. (n = 10). P < 0.001, significantly different from the dark phase value.
Figure 5.
Movement behavioral patterns, running distance and frequency of appearance at the running speed of mice in the third period.
(A) shows the behavior movement of a mouse under fasting in the third period. (B) shows the movement distance of the mice in the control (□) and fasting group (■). Values are Mean ± S.D. (n = 5). P < 0.001, significantly different from the control value. Compared to the control group, we observed that moving distance had increased significantly, and activities were enhanced in the fasting group. (C) the frequency of appearance at the running speed in control (□) and fasting (■). We compared the frequency distribution of each movement speed in each group. The interval of the X-axis is every 0.25 m. We observed that movement increased significantly and there was over-activity during fasting.
Figure 6.
Macroscopic images of brain tissue.
Macroscopically, upon dissection, we could not see any atrophy upon fasting and there was no change in wet weight of the brain. However, the surface of brain tissue appeared less glossy and seemed to have lost precision.
Figure 7.
Optical microscopy images of brain tissue.
Kluver–Barrera stained images of Frontal cross section of the brain (A) and the hippocampal region (B).
Figure 8.
Fluorescent treponemal antibody imaging of the brain tissue.
Brain sections of the subventricular zone (A) and hippocampus (B) were stained with immunostaining using nestin antibody. We observed the disappearance of nestin-positive cells in the fasting group.