Is structural remodeling in regions governing memory an univocal correlate of memory?

Advances in our ability to visualize changes in single neuron morphology during or after training have largely contributed to renew the interest into the structural basis of memory. Nevertheless the idea that structural alterations in memory-specific neural circuits can be univocally considered as correlates of memory needs to be carefully considered in view of evidence showing that a variety of sensorial/motor/emotional stimuli also alter the morphology of neurons in those circuits. The aim of this review is to examine the respective impact of memory vs other forms of experiences in triggering structural plasticity in the rodent brain, the challenge being to disentangle alterations due to the formation of declarative/relational memories from those developing in the same regions in relation to non-memory functions.