BDNF and pattern separation in the hippocampus

PEDRO BEKINSCHTEIN; LISA M. SAKSIDA; TIMOTHY J. BUSSEY

San Diego

Congreso; Society for neuroscience annual meeting 2010; 2010

Society for Neuroscience

To allow similar episodes to be distinguished in memory, the brain must form distinct representations of events. Thecomputational process for making representations for similar input patterns more orthogonal to and distinct from each otherhas been referred to as “pattern separation”. Recent studies have suggested that the brain region crucial for the process ofspatial pattern separation is the dentate gyrus (DG) of the hippocampus. It is largely unknown, however, what mechanismsand molecules underlie pattern separation. Brain-derived neurotrophic factor (BDNF) is a small dimeric secretory protein withan important role in excitatory transmission and plasticity in the adult brain. Here we show that an increase in BDNF in thedentate gyrus is associated with exposure to landmarks delineating similar, but not dissimilar spatial locations within an openfield. In contrast, no changes in Zif268, another plasticity-related protein, were detected, and no changes in BDNF levels werefound in other regions, for example CA1. Our results indicate that the expression of BDNF, possibly related to plasticityprocesses in the DG, may be important for the encoding and/or consolidation of overlapping spatial memory traces. We arecurrently testing whether blocking BDNF function can impair pattern separation.