PVALB and schizophrenia: Nevertheless, the identification of highly specific changes in subgroups of neurons, notably including the parvalbumin/GABA interneurons that have an important role in the inhibitory control of glutamatergic output, provides some elucidation of the relationships between neurotransmitter dysfunction and symptoms in schizophrenia (Fig. 1) as well as identifying potential new targets for the treatment of psychotic illness.