Press release

Study provides recommended techniques for handling lab mice to reduce anxiety

Improving handling techniques for laboratory mice helps reduce stress and anxiety, according to a study published today in the journal ‘Nature Methods’. The techniques identified in the study should lead to further improvements in the welfare of the mice.

Improving welfare conditions is a key element of the 'refinement' of laboratory procedures, one of the '3Rs' that aims to replace, reduce and refine the use of animals in experiments.

Currently, the standard procedure for handling mice is to pick up the mouse by its tail. However, scientists have not been aware that this can cause anxiety and stress to the mouse as mice appear to have an innate aversion to tail handling. Professor Jane Hurst and Rebecca West from the University of Liverpool have identified two other handling methods that significantly reduce anxiety and stress.

To assess anxiety-related behaviour in anticipation of handling, the researchers observed behaviour such as whether the mouse would voluntarily approach and interact with the handler immediately before and after daily handling, as well as urination and defecation during handling and a standard test of anxiety.

The first method involved bringing a clear acrylic tunnel towards the mouse. The mouse would voluntarily walk into the tunnel, allowing it to be lifted without direct contact.

The second method was for the handler to cup the mouse in his or her hands and allow it to walk freely over the open gloved hands. As unfamiliar mice tend to jump immediately away, Professor Hurst recommends closing the hands loosely around the mouse on the first time until it becomes accustomed to the experience.

The researchers also found that restraining a mouse by its tail did not cause undue stress or anxiety if the mouse had first been picked up using one of the above methods. When the mouse needed to be restrained more securely by the scruff of the neck, this did not reverse the taming effects of being handled on the open hands or using a tunnel.

"Animal welfare standards in UK laboratories are extremely high, but even so, it is very important that we always look for ways to improve conditions for the animals," says Professor Hurst. "The routine handling of laboratory animals is essential, so it is important that we do all we can to reduce any stress and anxiety. Using methods that minimise anxiety also reduces confounding factors and improves the responses during experiments, leading to more robust scientific outcomes."

The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), the National Centre for the 3Rs (NC3Rs) and the Wellcome Trust.

Dr Vicky Robinson, Chief Executive of the NC3Rs, comments: "This study shows that even the simple act of handling a mouse can cause it anxiety and stress, which in turn can affect experimental results. All researchers using mice are going to have to ask themselves whether picking the animal up by its tail is now the right thing to do."

Reference

Hurst JL, West RS. Taming anxiety in laboratory mice by non-aversive handling. Nature Methods 2010.

About the Biotechnology and Biological Sciences Research Council

The Biotechnology and Biological Sciences Research Council  (BBSRC) is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £470 million in a wide range of research that makes a significant contribution to the quality of life in the UK and beyond and supports a number of important industrial stakeholders, including the agriculture, food, chemical, healthcare and pharmaceutical sectors.

BBSRC provides institute strategic research grants to the following:

  • The Babraham Institute
  • Institute for Animal Health
  • Institute for Biological, Environmental and Rural Studies (Aberystwyth University)
  • Institute of Food Research
  • John Innes Centre
  • The Genome Analysis Centre
  • The Roslin Institute (University of Edinburgh)
  • Rothamsted Research.

The Institutes conduct long-term, mission-oriented research using specialist facilities. They have strong interactions with industry, government departments and other end-users of their research.

About the NC3Rs

The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) is an independent, scientific organisation which finds innovative solutions to:

  • replace animals in research with non-animal alternatives
  • reduce the number of animals used in experiments where their use is unavoidable
  • refine scientific procedures to minimise pain and suffering.

The NC3Rs drives advances in the 3Rs by taking a robust scientific approach, and bringing together experts from a diverse range of areas, including academia, industry, government and regulatory bodies. It funds high-quality research, organises workshops and symposia to disseminate and advance the 3Rs, and develops information resources and guidelines.

It was established in 2004 following a review by the House of Lords, and is funded by the Department for Business, Innovation and Skills (via the Medical Research Council and the Biotechnology and Biological Sciences Research Council), the Home Office, the Wellcome Trust, the Association of British Pharmaceutical Industry, GlaxoSmithKline, Unilever, The Dow Chemical Company, SC Johnson, Syngenta and Shell.

About the University of Liverpool

The University of Liverpool is a member of the Russell Group of leading research-intensive institutions in the UK. It attracts collaborative and contract research commissions from a wide range of national and international organisations valued at more than £98 million annually.

About the Wellcome Trust

The Wellcome Trust is a global charity dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust's breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests.