The immediate early gene Arc is required for pattern separation of non-spatial memories in the perirhinal cortex.

MAGDALENA MIRANDA; FACUNDO MORICI; FRANCISCO GALLO; NOELIA WEISSTAUB; PEDRO BEKINSCHTEIN

Congreso; XXX Congreso de la Sociedad Argentina de Neurociencias.; 2015

SAN

The immediate early gene Arc is required for pattern separation of object memories in the perirhinal cortex. AbstractSuccessful memory involves not only remembering information over time but also keeping memories distinct and less confusable. The ability to separate the components of memories into distinct memory representations relies on pattern separation, a computational process by which differences are amplified to disambiguate similar events. Despite the importance of this mnemonic function, the molecular mechanisms and signals necessary for the behavioral manifestations of this process remain unknown. Although pattern separation has been localized to the dentate gyrus of the hippocampus and shown to occur in a spatial domain, this cognitive function is thought to take place also during processing of other types of information. The perirhinal cortex (PRH) is involved in the acquisition and storage of object memories, and it was shown to be crucial for the resolution of tasks with ambiguous features. Thus, we hypothesized that this structure is involved in pattern separation of object memories. In this work, we used a PRH-dependent task and manipulated the load of pattern separation during information encoding. We showed that consolidation of pattern-separated object memories (and not spatial memories) depends on the expression of the gene Arc in the PRH during a time window, and that interaction between Arc and the neurotrophin BDNF is necessary for successful pattern separation. These findings suggest that Arc, an immediate early gene known to regulate synaptic plasticity and mediate memory formation, is involved in the molecular mechanisms underlying pattern separation.