The NMDA receptor modulator zelquistinel durably relieves behavioral deficits in three mouse models of autism spectrum disorder.

ABSTRACT

Autism spectrum disorders (ASD) are complex neurodevelopmental disorders characterized by deficient social communication and interaction together with restricted, stereotyped behaviors. Currently approved treatments relieve comorbidities rather than core symptoms. Since excitation/inhibition balance and synaptic plasticity are disrupted in ASD, molecules targeting excitatory synaptic transmission appear as highly promising candidates to treat this pathology. Among glutamatergic receptors, the NMDA receptor has received particular attention through the last decade to develop novel allosteric modulators. Here, we show that positive NMDA receptor modulation by zelquistinel, a spirocyclic ß-lactam platform chemical, relieves core symptoms in two genetic and one environmental mouse models of ASD. A single oral dose of zelquistinel rescued, in a dose-response manner, social deficits and stereotypic behavior in Shank3Δex13-16-/- mice while chronic intraperitoneal administration promoted a long-lasting relief of such autistic-like features in these mice. Subchronic oral mid-dose zelquistinel treatment demonstrated durable effects in Shank3Δex13-16-/-, Fmr1-/- and in utero valproate-exposed mice. Carry-over effects were best maintained in the Fmr1 null mouse model, with social parameters being still fully recovered two weeks after treatment withdrawal. Among recently developed NMDA receptor subunit modulators, zelquistinel displays a promising therapeutic potential to relieve core symptoms in ASD patients, with oral bioavailability and long-lasting effects boding well for clinical applications. Efficacy in three mouse models with different etiologies supports high translational value. Further, this compound represents an innovative pharmacological tool to investigate plasticity mechanisms underlying behavioral deficits in animal models of ASD.