PVALB and schizophrenia: In schizophrenia, a decrease in the number of PV-immunoreactive (PV+) neurons resulting from PV downregulation (initially presumed to result from Pvalb neuron loss) is observed in postmortem brains of affected individuals, as well as in mouse models of schizophrenia (Do et al., 2009; Powell et al., 2012).