Studies that require an animal to exercise to exhaustion require special consideration. The need for such extreme effort by an animal should be carefully defined and justified, and endpoints should be clearly established and well defined in the animal-use protocol. Specific behaviors, circumstances, or physiological markers should be established to alert the observer that a trial must be terminated. Continuous animal observation is essential near the time of the expected development of animal exhaustion. In all cases, accurate records of test conditions and of performance should be maintained for each animal, and they should be available to veterinary staff and the IACUC. Such records will allow day-to-day adjustment of testing, if warranted by an animal’s condition or ability.
A final consideration is the need to maintain sanitation of devices used for exercise or learning. Devices should be constructed of an impervious material to the greatest extent possible. A regular sanitation procedure and schedule should be established, maintained, and clearly documented. A thorough description of the sanitation process should be included in the animal-use protocol.
Short-term sleep loss in humans typically has no adverse physiologic consequences other than increasing sleepiness and impaired performance in some tasks (Horne, 1985; Naitoh et al., 1990). Because sleep is a homeostatic process, adverse effects associated with short-term sleep loss are probably alleviated simply by providing the opportunity to “catch up” on sleep (Everson, 1997; Everson et al., 1989), much as thirst is immediately relieved by taking a drink of water. In rats, biologically significant adverse effects of sleep deprivation have been reported only after sleep deprivation of more than 5 days (Everson and Toth, 2000).
Several approaches are used to produce sleep deprivation in laboratory animals. The method most widely used is probably the so-called “gentle-handling” technique. This method has been applied to rodents, rabbits, and cats and is usually used to cause loss of both rapid-eye-movement sleep (REMS) and non-rapid-eye-movement sleep (NREMS). The animals are under continuous observation by the experimenter and are physically roused by the experimenter whenever they either enter a state of electroencephalographically defined sleep or assume a sleeplike posture. Animals are generally aroused by such actions as tapping on the cage, providing novel objects, or prodding gently. As the duration of the deprivation period increases, particularly beyond a few hours during the species’ normal “rest” period, the experimenter must gradually increase the intensity or frequency of handling or of environmental stimulation to maintain arousal (of both the animal and the experimenter!). Because of its labor-intensive nature, the gentle-handling method of achieving sleep loss is rarely extended beyond a 24-hour period. Such short-term sleep loss does not appear to have marked adverse effects in humans or animals other than the progressive development of moderate to severe sleepiness, cognitive and performance impairment,