Ultrastructure of cortical synapses in the brain of schizophrenics.

The autopsy was performed in 225 cases of chronic schizophrenia. In 44 cases examination of the brain by light microscope revealed changes typical of Alzheimer's disease. The increased risk for the development of Alzheimer's disease in chronic schizophrenia is pointed out. In 8 schizophrenics where death occurred suddenly and unexpectedly electronmicroscopy of brain was carried out. Clusters of a great number of synaptic vesicles were found in presynaptic knobs in the brain cortex of the schizophrenics but not in the controls; the postmortal origin and/or fixation artefact origin of the clusters were excluded. The possible "immunologic dependent" clustering of synaptic vesicles is discussed. The new "modul concept" in the structure of the brain cortex is used to make the role of synapses in the mental process more clear.