FURTHER EVIDENCE OF ABNORMAL CYTOARCHITECTURE OF THE ENTORHINAL CORTEX IN SCHIZOPHRENIA USING SPATIAL POINT PATTERN ANALYSES

Previous studies have reported cytoarchitectural abnormalities in supe rficial laminae of rostral portions of the entorhinal cortex in schizo phrenia, including decreased densities of neurons, poorly formed layer II neuron islands, and apparent displacement of layer Ii-type neurons deep into layer Ill; however, findings have been controversial, given the qualitative nature of the descriptions and the normal heterogenei ty of cytoarchitecture of the region. The x, y coordinates of Nissl-st ained neurons were mapped in layers II, Ill, and V of entorhinal subdi vision ER in 8 prospectively accrued patients with schizophrenia and 8 nonneuropsychiatric controls. Indices of neuron dispersion, nearest n eighbor distances, and effective radius were determined. An abnormally clustered dispersion of neurons in layer III was present in schizophr enics compared to controls along with a reduced neuron effective radiu s, whereas the mean nearest-neighbor distance was normal, III layer II , there Mas a significantly increased effective radius, whereas other indices were normal. No between-group differences were noted in layer V for any variable, These data provide further evidence for subtle abe rrant cytoarchitecture in superficial laminae of the entorhinal cortex in schizophrenia and are consistent with neurodevelopmental models of abnormal neuronal pruning, ''miswiring'', and/or migration in the ill ness. (C) 1997 Society of Biological Psychiatry.