Such procedures include those that reduce a subject’s ability to interact socially or with the environment. Examples are procedures that result in impairment of sensory perception, limit an animal’s movement capacities, and impair cognitive abilities. After those procedures, appropriate accommodations should be made in an animal’s housing environment or access to enrichment devices to maximize the extent to which it can interact socially and with the environment. Such accommodations can include housing the animal in a social group where it will not be subject to aggressive attacks, giving it manipulanda that can be used with a particular sensory or motor deficit, and giving increased personal attention to an animal that can no longer be put in social housing (NRC, 1998).
On occasion, changes in standard husbandry practices are warranted by the scientific goals of an experiment. For example, cats may be reared in total darkness to determine the influence of visual experience on the development of the visual system (Lein and Shatz, 2000; Mower and Christen, 1985) or animals with lesions of the labyrinth may be housed in the dark to prevent visual compensation for altered vestibular cues (Fetter et al., 1988; Zennou-Azogui et al., 1996). In each of those types of neuroscience research, the animal protocol must ensure appropriate care and monitoring of the animal while maintaining the environmental requirements of the experiment; for example, food and water might be provided in the same locations before and after the lesion is produced.
Care of animals used in neuroscience or behavioral research often requires creativity and exceptions to an institution’s normal husbandry procedures. For example, the research team often provides all or much of the daily care of animals used in behavioral studies because of protocol-specific issues or special housing situations. If husbandry responsibilities (including cleaning and sanitization) are to be shared by the animal-care staff and the research staff, the role of each group must be clearly delineated and the care must be documented and freely available to both parties. Integrated husbandry responsibility can work well but only when all members of the team know and accept their roles. The IACUC is authorized to approve exceptions to standard husbandry practices that deviate from the Guide’s recommendations when the exceptions have a sound justification and appropriate performance standards are met.
Experimental designs for neuroscience or behavioral studies may involve the use of special environments, including periodic or chronic housing of animals in unusual, nontraditional settings; for example, animals may be reared in total darkness or exposed to omnidirectional sound, microgravity or hypergravity, hyperbaric, or magnetism-free environments. The need to use a special environment may require housing multiple species in close proximity. The Guide recommends “physical separation of animals by species to prevent interspecies disease transmission