GRIN2A and schizophrenia: Only two groups have measured NR1 and PSD-95 protein in synaptosomal extracts from people with schizophrenia.28,35 The first study used immunoprecipitation of PSD-95 from PSD-enriched fractions of prefrontal cortex followed by western blotting to detect increased amounts of NMDA receptor NR1 and NR2A subunits associated with PSD-95 in 10 elderly individuals with schizophrenia.