Schizophrenia-like phenotypes and long-term synaptic plasticity impairment in GluN2A-transgenic mice

While N-methyl-D-aspartate receptor (NMDAR) hypofunction has been suggested as a hallmark of schizophrenia, the role of subunit-specific dysregulation such as GluN2A overexpression remains poorly understood. The present study comprehensively investigated the impact of GluN2A overexpression on behavioral phenotypes, cognitive functions, and synaptic plasticity in transgenic mice with forebrain-specific overexpression of the GluN2A subunit (GluN2A-TG). Behavioral assessments revealed schizophrenia-like phenotypes, including prolonged stereotypic movement duration, impaired sensorimotor gating, reduced social interaction, and diminished nest-building activity in GluN2A-TG mice. Consistently, GluN2A-TG mice exhibited not only deficits in spatial working memory and olfactory working memory but also impaired associative learning. In addition, both long-term potentiation and long-term depression were significantly attenuated in the prefrontal cortex (PFC) of GluN2A-TG mice. Furthermore, electrophysiological analysis of NMDAR-mediated excitatory postsynaptic currents in PFC neurons revealed altered kinetics characterized by a faster decay time and significantly increased amplitude in GluN2A-TG mice. Collectively, these findings suggest that GluN2A overexpression may induce schizophrenia-like phenotypes via impairing NMDAR-dependent long-term synaptic plasticity in the PFC, likely due to altered NMDAR subunit composition leading to disrupted calcium signaling dynamics. These results provide critical insights into the pathological role of GluN2A in schizophrenia.