Individually housing animals, even for a short period, is known to have a negative influence on behavior, learning ability, and physiology. Group-housed rodents are better able to cope with stress through improved behavioral and physiological responses. Unfortunately, many experiments, including those designed to measure behavior, circadian activity, and/or sleep, necessitate single-housing due to technological restrictions. Automated delivery of an experimental intervention, such as gentle nudging to disturb sleep, is easily accomplished with single animals but is complicated in group-housing environments. The overall goal of this application is (1) to develop a novel cage enclosure designed for group housing of multiple, physically similar animals with long-term computer-aided video monitoring and radio frequency identification (RFID) to correctly and accurately identify and track individual animals within a group of three or more and (2) to automatically apply an intervention stimulus to one or more animals within the group. This system will employ a robotic arm situated directly above the cage, which, when tied to the video tracking module and RFID reader, can selectively apply an intervention stimulus (i.e., gentle nudging for sleep deprivation) to a specific animal based on state-specific feedback. The defined state may be classified using data collected via video tracking, wireless electroencephalograph (EEG) measurement, wireless biosensor measurement of specific neurochemicals, or other wireless physiological measurements. The system will be configurable so that the intervention stimulus may be applied to an individual animal based on physiological parameters defined by the researcher. In Phase I of this application, we will design and test a prototype enclosure for individual animal identification and stimulus in a small group of rats. Phase II will continue this development by testing and refining animal tracking and behavior involving multiple rats and mice, increasing the accuracy of video tracking, and increasing the types of intervention stimuli available to the researcher. At the completion of Phase II, we will have a complete, turn-key hardware and software solution that will be commercially available to the research community.
This project has the potential to give researchers a new tool to overcome social isolation stressors in their experiments and can be used across many different research models. For example, the system can be used to eliminate the unwanted effects of social isolation on sleep deprivation and sleep fragmentation studies helping an estimated 40 million Americans who suffer from chronic, long-term sleep disorders and the 20 million who experience occasional sleeping problems. Poor sleep alone accounts for an estimated $16 billion in medical costs each year and the indirect costs of lost productivity and other factors are known to be much higher.