SCHIZOPHRENIA AND ANTEROVENTRAL THALAMIC NUCLEUS - SELECTIVE DECREASEOF PARVALBUMIN-IMMUNOREACTIVE THALAMOCORTICAL PROJECTION NEURONS

This study was designed to examine possible anatomical changes of thal amocortical circuits in schizophrenics. Previous immunocytochemical st udies have shown that parvalbumin, a calcium-binding protein, occurs i n thalamocortical projection neurons, but not in GABAergic interneuron s in the anteroventral thalamic nucleus (AN). Using parvalbumin-immuno cytochemistry we investigated the densities of thalamocortical project ion neurons in the AN of schizophrenic cases (n = 12) and controls (n = 14). The densities of all neurons in the AN were estimated by Nissl- staining. The majority of thalamocortical projection neurons in AN wer e identified by parvalbumin-immunoreaction. Significantly reduced dens ities of thalamocortical projection neurons were estimated in the righ t (P = 0.003) and left AN (P = 0.018) in schizophrenic subjects. The d ensities of all neurons in right and left AN were also diminished in s chizophrenics; however, these decreases did not reach statistical sign ificance. The reductions of parvalbumin-positive thalamocortical proje ction neurons were not correlated with the length of disease, this fin ding supporting the neurodevelopmental etiology of structural abnormal ities in schizophrenia. (C) 1998 Elsevier Science Ireland Ltd.