NMDA receptors (NMDARs) are ionotropic receptors crucial for brain information processing. Yet, evidence also supports an ion-flux-independent signaling mode mediating synaptic long-term depression (LTD) and spine shrinkage. Here, we identify AETA (Aη), an amyloid-β precursor protein (APP) cleavage product, as an NMDAR modulator with the unique dual regulatory capacity to impact both signaling modes. AETA inhibits ionotropic NMDAR activity by competing with the co-agonist and induces an intracellular conformational modification of GluN1 subunits. This favors non-ionotropic NMDAR signaling leading to enhanced LTD and favors spine shrinkage. Endogenously, AETA production is increased by in vivo chemogenetically induced neuronal activity. Genetic deletion of AETA production alters NMDAR transmission and prevents LTD, phenotypes rescued by acute exogenous AETA application. This genetic deletion also impairs contextual fear memory. Our findings demonstrate AETA-dependent NMDAR activation (ADNA), characterizing AETA as a unique type of endogenous NMDAR modulator that exerts bidirectional control over NMDAR signaling and associated information processing.
GrantsMiniste re de la Recherche, de l'Enseignement Superieur et de l'Innovation French Association France Alzheimer French Fondation Alzheimer Agence Nationale de la Recherche Flag ERA JTC Investments for the Future LABEX SIG-NALIFE Fondation pour la Recherche Medicale (FRM) European Research Council Institut Neuromod, Universite Cote d'Azur MRC EUFP17 Marie Curie Actions Wellcome Trust BBSRC NIH Deutsche Forschungsgemeinschaft Walter Benjamin project Centre National de la Recherche Scientifique (CNRS)