Based on the view that without forgetting normal brain function would not be possible, the need arose to study the behaviour of rodents within ethologically valid settings. Standard laboratory housing deprives rats of opportunities to express the full range of their natural behaviours, and their physiology reflects this. Thus, experiments with rats living in standard housing, with little change to daily routines, may limit the epistemological and translational value of studies on the role of endogenous forgetting in memory.

Within the funding portfolio of SIDB, together with Dr Peter Kind, we developed an ethologically valid housing system for rats in the laboratory. Our facility at the University of Edinburgh now houses five Habitats. The defining characteristics of The Habitat are that rats are continuously video recorded, that they can be housed in large groups (up to 64 animals), and that thanks to its modularity novelty can be easily provided by rearranging the layout, generating environments of varying complexity, which can be accomplished without tools and by a single person within minutes. Furthermore, several Habitats can be linked, such that one can serve as the “burrow”, and other ones as the “outside world”, where rats, for example, can search for food, or explore novel environments.

We also developed specialized modules in which rats can self-recruit to experimental tasks, without any intervention from human experimenters affecting animal behaviour. For example, we use a “tube test” mod- ule to assess social dominance; in a module with a touch screen rats can receive rewards for correct recognition responses; and we use a module in which rats must cooperate to receive rewards. Our Habitat is the only system available with these combined capacities.

While The Habitat will notably improve animal welfare and husbandry in laboratory settings, it will also allow us to ask pressing questions in behavioural neuroscience, such as whether animal housing and enriched experiences influence basic memory processes. For example, we will test whether this type of housing affects the timeline of memory consolidation, how prior experiences affect learning and memory, and whether epigenetic changes following learning and memory formation in common behavioural tasks will be different between rats living in The Habitat and those living under standard conditions. We will further explore whether there are critical phases during lifelong development that are sensitive to naturalistic housing, focusing on early development and aging.

This research project may produce a series of ground-breaking insights into the role of the environment, or “Umwelt”, in basic cognitive processes, with high translational value.