To develop an automated non-surgical system, which can be used in rats and mice, to measure activity and temperature over a minimum of a 24 hour period.
Measurement of the activity of individual rats or mice in their home cage provides useful information in studies from basic research through to drug discovery and development. This includes:
- Detecting and assessing toxicological effects (for example effects on the central nervous system) of candidate drugs, including physical dependence;
- Characterization of agents targeting disorders of the CNS;
- Behavioural phenotyping of genetically altered animals;
- Studies of circadian rhythms.
Measurement of body temperature in rodents may also be used in each of the research applications above; particularly for some toxicology studies and the assessment of physical dependence. Activity and temperature can currently only be measured separately, unless surgically implanted telemetry devices are used; however the surgery required places an additional welfare burden on the animals. Activity can be measured non-invasively using transparent cages and photocell beams or infrared movement sensors, or by placing the cages on mechanical sensor platforms. However, this requires animals to be singly housed, which is not ideal for social species such as rats and mice which live in groups.
Video tracking systems, with individuals marked with different colours, can be used for group-housed rodents but these methods are not readily incorporated into standard caging with wire mesh lids, especially when measuring simultaneously from multiple cages; also, video tracking in darkness requires infrared lighting, which would not enable discrimination between individuals marked with different colours. The aim of this challenge is to develop an integrated system which combines measurement of activity and temperature in rodents that can be used with group housing and without surgery.ID microchip transponders which measure temperature already exist and may potentially be utilised for this challenge. These chips are about 14 mm x 2 mm, and are injected subcutaneously in the nape of the neck. Examples include the IPTT-300 (PLEXX, Netherlands; BioMedic Data Systems Inc., USA). Accelerometers have been used to record and characterize behavioural movements in rodents, but so far only when worn externally.
The development of a non-surgical, automated approach to measure activity and temperature in animals supports reduction and refinement by avoiding the need for surgery or single housing. It would enable incorporation of these additional measurements into existing study types, thereby reducing the number of separate standalone studies. It could potentially impact on the welfare of thousands of animals. More broadly, this technology could also be used to provide additional information for other studies where early identification of animals with subdued activity or changes in body temperature could be used to improve humane endpoints.
Full Challenge information
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