Wilm’s tumor 1 promotes memory flexibility

Under physiological conditions, strength and persistence of memory must be regulated in order to produce behavioral flexibility. In fact, impairments in memory flexibility are associated with pathologies such as post-traumatic stress disorder or autism; however the underlying mechanisms that enable memory flexibility are still poorly understood. Here we identified the transcriptional repressor Wilm’s Tumor 1 (WT1) as a critical synaptic plasticity regulator that decreases memory strength, promoting memory flexibility. WT1 was activated in the hippocampus following induction of long-term potentiation (LTP) or learning. WT1 knockdown enhanced CA1 neuronal excitability, LTP and long-term memory whereas its over-expression weakened memory retention. Moreover, forebrain WT1-deficient mice showed deficits in both reversal, sequential learning tasks and contextual fear extinction, exhibiting impaired memory flexibility. We conclude that WT1 limits memory strength or promotes memory weakening, thus enabling memory flexibility, a process that is critical for learning from new experience.