Depression is a disabling illness that affects almost 264 million people worldwide. Key symptoms include a loss of interest or pleasure in every day activities as well as impaired sleep, concentration and appetite. Available antidepressant treatments are effective in less than half of the people who take them so there is a need to develop new and better antidepressants.
Researchers at Bath have been investigating the possibility of a new class of antidepressant molecules for several years. Mice are used in this research. The video below shows an example of a mouse in a ‘forced swim test’ as part of this research, although no experiments using the forced swim test have taken place at the University since 2019.
Mice are gently placed in a large beaker of warmed water for six minutes. During the test mice show swimming behaviour (horizontal movements) and climbing behaviour (more vertical movements of the forepaws against the side of the beaker) and periods of immobility (floating with minimal activity required to keep the mouse’s head above water). At the end of the test the mice are removed, gently dried and warmed. On returning to their home cage, mice show a range of normal behaviours including grooming and interaction with cage mates.
Typically, a mouse given an antidepressant medicine such as a selective serotonin reuptake inhibitor (SSRI, e.g. Prozac) will spend less time immobile in the test and more time engaged in swimming and climbing behaviours. Testing compounds with new chemistry in the forced swim test allows researchers to identify potential new antidepressant-like medicines. The compounds must go through much more testing and development, but the forced swim test is a key indicator of the potential activity of a new compound.
The University of Bath fully supports the principles of the "3Rs": Replacement, Refinement and Reduction of animals in research and endorses the ARRIVE guidelines, developed to improve the design and reporting of animal experiments.
We make considerable use of other experimental models such as tissue culture and computer modelling but certain properties are shown only by whole animals. In these instances we ensure that animal numbers are kept to the minimum possible to provide credible data and that all procedures are as refined as possible to reduce any possible suffering.
In the UK, research involving living non-human vertebrates is regulated by the Home Office under the Animals (Scientific Procedures) Act 1986 incorporating the EU Directive 2010/63/EU, and all work is carried out under licence. Projects are rigorously reviewed, initially by the local Animal Welfare and Ethical Review Body (AWERB), which includes scientists, vets, animal welfare officers and lay members, and finally by the Home Office Inspectorate (Animals in Science Regulation Unit). This ensures that, for any proposed project, the benefits from the research outweigh any possible discomfort to the animals.
The University of Bath is a signatory of the Concordat on Openness on Animal Research and is committed to enhancing our communications with the media and public about our research using animals.