Parvalbumin-immunoreactive neurons are reduced in the prefrontal cortex of schizophrenics.

Recent studies have provided evidence for a functional impairment of gamma-aminobutyric acid (GABA)-containing interneurons in the prefrontal cortex of schizophrenics. This evidence includes reported deficits of basket and chandelier cells, which are known to contain the calcium-binding protein parvalbumin. Using a monoclonal antibody against parvalbumin we investigated possible changes in this subpopulation of neurons in the prefrontal cortex of schizophrenic cases and controls. Significantly reduced numbers of parvalbumin-immunoreactive neurons were observed in laminae III and IV, while no difference was detected in cortical width. Our findings are consistent with damage following a toxic insult, occurring during a developmental 'window of vulnerability' and specifically affecting this subpopulation of GABAergic neurons.