ABNORMALLY HIGH NEURONAL DENSITY IN THE SCHIZOPHRENIC CORTEX - A MORPHOMETRIC ANALYSIS OF PREFRONTAL AREA-9 AND OCCIPITAL AREA-17

Background: In the past two decades, gross morphologic changes have be en uncovered in the schizophrenic brain, eg, increased ventricular wid th and decreased cortical volume; however, relatively little is known about the area-specific and laminar density of cells in the schizophre nic cortex, particularly in prefrontal areas. Method: A direct, three- dimensional counting method was used to determine cell density in 16 b rains from patients with schizophrenia, 19 from normal subjects, six f rom patients with schizoaffective disorder, and nine from patients wit h advanced-stage Huntington's disease. Results: Increased neuronal den sity was found in prefrontal area 9 (17%) and occipital area 17 (10%) in the schizophrenic brains. In area 9, neuronal density was increased in layers III to VI; cell packing of pyramidal and nonpyramidal neuro ns was elevated. Cortical thickness in the schizophrenic brains was sl ightly but not significantly reduced in both areas, with a disproporti onate reduction in layer V in area 9. In contrast, brains with Hunting ton's disease exhibited markedly higher glial density (50%) and drasti cally reduced cortical thickness (28%). Conclusion: Abnormally high de nsity in the cerebral cortices of schizophrenics suggests that neurona l atrophy is the anatomic substrate for deficient information processi ng in schizophrenia.