In this section

You could monitor the ambulatory activity of each individual rat within a group in a standard home cage over 24 hours or longer?

The ActualHCA system monitors individual rodents by using an RFID chip smaller than a fingertip. There is no need for surgery: it is injected subcutaneously. The chip is then tracked by the baseplate monitor under the cage. Infrared lighting ensures that data can be consistently collected. This combination allows the rodents to be tracked individually and makes them easily identifiable on the footage.

The recording process is surprisingly simple. Light-dark phase video is picked up from the individual animals and transmitted to a mini-computer that, along with its power supply, is attached to the camera and uploads the data to a mobile server unit every few minutes. Below, you can see what some of the activity data from the cage looks like.

 

Rodents fare much better in group environments, and this means they can be left to their own devices while under observation, reducing the signs of stress that can interfere with results. The system is so finely tuned that rodents can even be mixed into different treatment groups and still be identified, allowing for a reduced number of animals that carries the same statistical power as a larger number.