WaterR: A tool for better management and monitoring of rodent fluid intake

Understanding how signals in the brain guide our behaviour is vital to help combat many neurological and neurodegenerative diseases. These kinds of experiments normally require motivational drive to help the animals learn a behavioural task (much like training a dog) and liquid treats are one of the best motivators to use. However, it is difficult to ensure that the animal is just thirsty enough, without putting them in a state where they are unnecessarily thirsty. To improve these procedures, we have developed a low-cost device for automatically dispensing just the right amounts of water. In this project we will work with groups across the UK to trial improvements to the device to make sure it can easily be used in any lab. We will then publish the plans online for making the device and we will hold workshops to tell others about it, to make sure as many labs as possible start using this approach.

Most rodent behavioural experiments require motivation to encourage animals to learn and perform experimental tasks. In many cases, it is now recognised that motivation driven by restricting access to fluids is the most suitable approach. However, ensuring that motivation is sufficient to meet the scientific aims, without exposing animals to unnecessarily high levels of thirst is difficult and often impractical. Automating the process therefore offers the opportunity to significantly refine current practice. To meet this need, we have developed and established a low-cost device (called WaterR) for automated home-cage water delivery for rodents. The device is simple to make in the lab and can be easily adapted to meet different experimental needs.
This project will refine fluid control practice by enabling the widespread adoption of the automated water delivery device we have developed. To achieve this, we have partnered with ambassador laboratories from four key hubs of in vivo research across the UK (Bristol, Oxford, UCL, and Edinburgh). We will work with these groups to adapt WaterR to make it readily accessible for any group to adopt. We will then produce and release the plans online and run workshops to publicise the device and aid adoption.

The primary impact of the project will be the refinement of procedures involving controlled access to fluids. The introduction of new research techniques has led to a sharp increase in the use of water-restriction as a motivational tool in behavioural research, but practical hurdles make it difficult to implement the most refined methods. By automating the process, our device will minimise the restriction of access to fluids for each animal and in some cases, this may result in a reduction in overall severity (from moderate to mild). Our conservative estimates predict that the refinements will reduce the cumulative effects experienced by ~6500 rodents per year in the UK and >40,000 internationally (see case for support for breakdown of the calculations).
A further impact of the project will be in helping to share best-practices and standardise procedures. The rapid rise in use of this technique has led to little standardisation across groups and institutions. The project will build a network of in vivo research stakeholders and enable us to gather and disseminate the latest and most refined fluid-control methods; these will be published as a methods paper and presented at conferences. Automating fluid control will help to reduce variability in motivational levels between animals; as a result, we expect to increase robustness and reproducibility of results and reduce the number of animals needed for experiments.