How you handle mice
affects response to rewards.
Science improves too!
There is an increasing body of research to suggest that handling laboratory mice by the tail is both bad for their welfare and the science that the mice are studied for. Tail handling has negative impacts on mouse behaviour and physiology, with tunnel and cupping handling techniques resulting in behavioural improvements across various common behavioural bioassays, including the elevated plus maze, the open field test and the habituation-dishabituation paradigm.
Now new research suggests that handling is also important for reward-based behavioural assays. A study by Clarkson et al (2018) examined mouse response to sucrose solution (a common reward). They found that tail handled mice showed a reduced response to the sucrose than the tunnel handling method, a finding indicative of the tail handled mice having a ‘decreased responsiveness to reward and potentially a more depressive-like state’.
Across eight years and five research papers, from three distinct research groups in two countries, the field of laboratory mouse research has been irrevocably changed. Combined, the research suggests that tail handling results in poor animal welfare and potentially erroneous scientific results. The National Centre for the Replacement, Refinement & Reduction of Animals in Research now has extensive information on mouse handling techniques, example videos, tips and testimonials for researchers and animal carers to find out more about changing their current mouse handling methods to the tunnel or cupping techniques.
Original research: http://dx.doi.org/10.1038/s41598-018-20716-3