Refining the use of head fixation and fluid control in rodents
A new paper summarises the recommendations of an NC3Rs working group on high-yield rodent behaviour. The paper focuses on the use of fluid control and head fixation in mice, two procedures with clear animal welfare impacts but where until now, there was little guidance or best practice recommendations.
Head fixation and fluid control are typically applied to enable the collection of neuronal recordings and behavioural data in mice in studies using sensory stimuli that involve many hundreds of trials. Surgically-implanted head fixation devices to restrain the animals can cause pain and suffering because of the nature of the procedures involved and the risk of post-operative infection. Each testing session whilst head-fixed may last for many hours and studies can last weeks or months. When a large number of trials are required, fluid control is often used to motivate animals and the size of the fluid rewards limited to avoid the animal becoming satiated before enough data has been collected. This also has the potential to add to the welfare burden on the animals and requires careful and prolonged monitoring of the animals.
The use of fluid control and head fixation, alone or in combination, is broadening and these procedures are now used across the neurosciences. This makes it an ideal time to review their use and make recommendations to provide best practice advice to those new to these techniques as well as those already using them as part of their research.
The paper is the result of the deliberations of an expert NC3Rs working group that includes representatives from the scientific, veterinary and animal technician communities. The work was supplemented with extensive literature reviews and an international survey of users that includes responses from UK and overseas institutions. A summary of this work, results from the survey and recommendations made by the group can be found in the new paper.
Barkus et al. (2022). Refinements to rodent head fixation and fluid/food control for neuroscience. J Neurosci Methods 381:109705 doi: 10.1016/j.jneumeth.2022.109705.
The recommendations are divided into three sections: head fixation surgery, motivation and reward which includes discussion of fluid control, and refining the behavioural set-up. Whilst the focus is research involving the use of head fixation in mice, discussion of topics such as postoperative care and habituation to testing are also included and will be of interest to those performing any stereotactic surgery and/or behavioural testing in rodents.
The paper is supported by additional material, including a detailed surgical standard operating procedure and example welfare monitoring sheets.
We will be disseminating this work and engaging with the community as part of events such as the British Neuroscience Association Festival of Neuroscience, 23 – 26 April 2023. During the session you will be able to hear from members of the working group as well as other researchers in the area discussing their researchers and how they have refined their use of these procedures.