The 3Hs initiative: Handling, housing and habituation

Use of animal models is pervasive across neuroscience research. Good quality research data is underpinned by good animal welfare, which can be achieved through methods of refinement. We have developed a framework that considers the lifetime experience of the laboratory animal and seeks to improve their welfare by targeting the 3Hs: Housing, Handling and Habituation.To promote natural behaviours both rats and mice are housed in highly enriched caging with sexually mature male mice housed individually to reduce social stress. Recognising the space restrictions of standard rodent caging, we also incorporate access to playpens for added enrichment. We have modified our handling and restraint techniques to eliminate the need for physical restraint in rats or tail handling in mice including for substance administration. We have also developed a voluntary oral dosing protocol that eliminates the need for restraint and gavage. We have implemented habituation protocols including exposure to experimental apparatus combined with positive reinforcement to develop more positive associations before study onset. In order to objectively assess the welfare benefits of these approaches, we use our affective bias test and reward learning assay which provide a sensitive measure of both short term and chronic changes in affective state respectively.Using these methods alongside quantification of stress hormones, we demonstrate positive welfare effects of these refinements. By addressing the animal’s relationship to both its environment and research staff we can reduce the negative impacts of cumulative stress across the entire lifetime of the animal.