Effects of enforced wakefulness upon the growth and the maze-learning performance of white rats.

Abstract

An exptl. group of 48 animals, [male][male] and [female] [female] , were kept awake for 20 hrs. a day on a treadmill surrounded by water. Three control groups were used: (a) animals living in cells identical with those of the exptl. group except that the treadmills were kept stationary (n [long dash] 21); (b), as in (a) except that the animals were forced to exercise as much in 12/3 hrs. as the exptl. animals did in 20 hrs. (n = 23); (c) a laboratory group living in regular laboratory cages (n = 55). (All n''s refer to survivors, since some animals in each group died during the course of the expt.) The animals were set to the exptl. (or control) regime at 30 days of age; and 20 days later training was initiated on a water maze, other exptl. conditions remaining unchanged. The growth curves of the 3 control groups are similar and apparently normal for both [male] [male] and [female] [female]. Those of the exptl. group, however, rise much less rapidly than those of the control groups from age 30 days on, and at about 72 days become nearly flat. With respect to learning performance in the water maze, the wakeful animals were superior to all other control groups on all criteria: trials to learn, errors, distance traveled, time, and speed. The wakeful animals became highly irritable during the course of the expt. They were less able to withstand a further 24-hrs. of enforced wakefulness than were the controls.