MAPT and schizophrenia: In summary, our results showed that clozapine combining with PQQ treatments could ameliorate the memory deficits in MK-801 induced schizophrenia rats partially by reducing the expression of NMDAR1 and MGLUR3, decreasing hippocampal tau hyperphosphorylation and inhibiting apoptosis through Akt/GSK-3β signaling pathway.