Role of the cell adhesion molecule F3/contactin in hippocampal synaptic plasticity and memory in old mice

Introduction: F3/contactin is a cell-adhesion molecule belonging to the immunoglobulin superfamily involved in building and maintaining synapses during brain development. Previous findings showed that F3/contactin might increase neurotransmitter release, and that hippocampal levels of F3/contactin decrease with age concomitantly with cognitive decline. Aim: The aim of this study was to investigate the role of F3/contactin in hippocampal synaptic plasticity and memory in aged mice. Methods: We used transgenic (Tg) mice in which F3/contactin expression is driven by TAG-1 gene regulatory sequences (TAG/F3 mice) undergoing an increased expression of F3/contactin in the forebrain in late development. We performed electrophysiological and behavioral studies to evaluate hippocampal synaptic plasticity and memory at different ages. Results: We found that old TAG/F3 homozygous mice (15-18 months) presented an improvement of LTP and memory compared with wild type littermates, whereas young Tg animals (3-5 months) showed normal behavioral and electrophysiological performances. Conclusions: Our data suggest that overexpression of F3/contactin determines an improvement of hippocampal synaptic plasticity and memory in old mice. These findings might be relevant for new therapeutical approaches against the impairment of learning and memory during aging.