RRC ID 85224
Author Hosseini H, Evans-Martin S, Jones KS.
Title Global Grin2a loss causes divergent impairments to PV+ and SST+ interneurons and alters gamma oscillations in prefrontal cortex.
Journal Neurobiol Dis
Abstract BACKGROUND:Loss-of-function mutations in the Grin2a gene, encoding the GluN2A subunit of NMDA receptors, confer elevated schizophrenia (SCZ) risk. Although GluN2A is expressed in multiple interneuron subtypes, its role in inhibitory circuit function remains incompletely understood. Recent genetic and transcriptomic studies implicate somatostatin-positive (SST+) interneurons in SCZ pathophysiology, raising the question of whether Grin2a deletion differentially affects SST+ and parvalbumin-positive (PV+) cells.
METHODS:We utilized global Grin2a knockout (KO) and heterozygous (HET) mice to investigate how GluN2A deficiency affects inhibitory dynamics in the prelimbic (PrL) medial prefrontal cortex (mPFC). Immunohistochemistry quantified interneuron density, while slice electrophysiology and optogenetics assessed inhibitory postsynaptic current (IPSC) amplitude and kinetics, quantal GABA release, and PV+- and SST-driven gamma-band oscillations (GBOs).
RESULTS:Grin2a KO and HET mice exhibited increased PV+ and SST+ interneuron density and a shift in excitatory-inhibitory (E/I) balance favoring inhibition. PV+ interneurons displayed functional impairments characterized by prolonged IPSC decay, elevated asynchronous GABA release, and enhanced PV-driven gamma-band oscillations (GBOs), consistent with impaired presynaptic calcium handling. In contrast, SST+ interneurons exhibited increased IPSC amplitudes without alterations in short-term plasticity or oscillatory drive, suggesting modulation of inhibitory tone without affecting network synchrony.
CONCLUSION:GluN2A loss appears to disrupt inhibitory networks through distinct cell-type-specific mechanisms-presynaptic dysfunction in PV+ cells and postsynaptic enhancement from SST+ cells. PV+ dysfunction aligns with gamma synchrony impairments linked to SCZ cognitive flexibility, while SST+ alterations may contribute to impaired feedback inhibition and sensory deficits. These findings clarify GluN2A's role in interneuron subtype function and network stability in SCZ.
Volume 212
Pages 106977
Published 2025-8-1
DOI 10.1016/j.nbd.2025.106977
PII S0969-9961(25)00193-7
PMID 40436282
MeSH Animals Gamma Rhythm* / physiology Inhibitory Postsynaptic Potentials / physiology Interneurons* / metabolism Interneurons* / physiology Male Mice Mice, Inbred C57BL Mice, Knockout Parvalbumins* / metabolism Prefrontal Cortex* / metabolism Prefrontal Cortex* / physiopathology Receptors, N-Methyl-D-Aspartate* / deficiency Receptors, N-Methyl-D-Aspartate* / genetics Receptors, N-Methyl-D-Aspartate* / metabolism Somatostatin* / metabolism
Resource
Mice RBRC02256