Environmental enrichment in middle age rats improves spatial and object memory discrimination deficits.

Changes in memory performance are one of the main symptoms of normal aging. The storage of similar experiences as different memories (ie. behavioral pattern separation), becomes less efficient as aging progresses.

Endocytosis is required for consolidation of pattern-separated memories in the perirhinal cortex.

Introduction: The ability to separate similar experiences into differentiated representations is proposed to be based on a computational process called pattern separation, and it is one of the key characteristics of episodic memory. Although pattern separation has been mainly studied in the dentate gyrus of the hippocampus, this cognitive function if thought to take place also in other regions of the brain. The perirhinal cortex is important for the acquisition and storage of object memories, and in particular for object memory differentiation.

Molecular mechanisms within the dentate gyrus and the perirhinal cortex interact during discrimination of similar nonspatial memories.

Differentiating between similar memories is a crucial cognitive function that enables correct episodic memory formation. The ability to separate the components of memories into distinct representations is thought to rely on a computational process known as pattern separation, by which differences are amplified to disambiguate similar events. Although pattern separation has been localized to the dentate gyrus (DG) of the hippocampus and shown to occur in a spatial domain, this cognitive function takes place also during processing of other types of information.