The spontaneous location recognition task for assessing spatial pattern separation and memory across a delay in rats and mice

AMY REICHELT; CECILIA KRAMAR; OLIVIA R. GHOSH-SWABY; PAUL A. S. SHEPPARD; BRIANNE A. KENT; PEDRO BEKINSCHTEIN; LISA M. SAKSIDA; TIMOTHY J. BUSSEY

NATURE PROTOCOLS

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2021

1754-2189

Keeping similar memories distinct from one another is a critical cognitive process without which we would have difficultyfunctioning in everyday life. Memories are thought to be kept distinct through the computational mechanism of patternseparation, which reduces overlap between similar input patterns to amplify differences among stored representations. Atthe behavioral level, impaired pattern separation has been shown to contribute to memory deficits seen inneuropsychiatric and neurodegenerative diseases, including Alzheimer?s disease, and in normal aging. This protocoldescribes the use of the spontaneous location recognition (SLR) task in mice and rats to behaviorally assess spatialpattern separation ability. This two-phase spontaneous memory task assesses the extent to which animals candiscriminate and remember object locations presented during the encoding phase. Using three configurations of the task,the similarity of the to-be-remembered locations can be parametrically manipulated by altering the spatial positions ofobjects?dissimilar, similar or extra similar?to vary the load on pattern separation. Unlike other pattern separation tasks,SLR varies the load on pattern separation during encoding, when pattern separation is thought to occur. Furthermore,SLR can be used in standard rodent behavioral facilities with basic expertise in rodent handling. The entire protocol takes~20 d from habituation to testing of the animals on all three task configurations. By incorporating breaks between testing,and varying the objects used as landmarks, animals can be tested repeatedly, increasing experimental power by allowingfor within-subjects manipulations.