22 Positions in the cortex are occupied in the sixth

month, and the matrix is entirely depleted in the seventh.11 Further details of the early development, of the entorhinal cortex in humans remain controversial. In one study,23 78 out. of 120 cases of schizophrenia showed major cytoarchitectural abnormalities in the rostral portion of the entorhinal cortex. These abnormalities extended in the anteroposterior direction to the frontobasal area rostrally, but. caudally only to the level of a section through the inferior horn of the lateral ventricle and the anterior portion of the hippocampus, where the cytoarchitecture became increasingly Inhibitors,research,lifescience,medical normal. Inhibitors,research,lifescience,medical The most pronounced abnormalities were found in the anterior sections. An increased number of glia was not. observed anywhere.23-25 Standard neuropathological CDK assay methods were used.24,26 The inferior portion of the left hemisphere, sectioned at the level of the amygdala nucleus, was embedded in celloidin; 20-µm thick celloidin sections were stained with Nissl and Heidenhain-Woelcke stains for histological investigation, and 16 cases with other clinical diagnoses were selected for use as controls. Graded scries of cases and controls were used to obtain

an overall Inhibitors,research,lifescience,medical view of the extent of the histological abnormalities. The most pronounced findings were cytoarchitectural abnormalities in layers Pre-α and Pre-β; abnormalities Inhibitors,research,lifescience,medical of Pre-α in the central region often consisted of only a few characteristic island-like formations. These layers were irregularly constructed. Because the structural abnormalities were variable, a uniform pathological picture could not be obtained. While only the Pre-α and Pre-β (layer II and layer III) layers were affected in “mild” cases, the entire cortex was affected in “severe” cases. In the Inhibitors,research,lifescience,medical severe cases, layers III and IV (the Pri-layers) were depleted of approximately 20% and 40% of their neurons, respectively,

in comparison with controls (Figure 2) 24 Figure II. Focal malformation in the rostral entorhinal region in a patient with chronic schizophrenia. A. Rostral cortical fields in a serial histological out study, fourth stage of the series, layers II and III (Pre-α and Pre-β); layer Pre-α … The most, commonly encountered abnormalities of layer II (Pre-α) and layer III (Pre-β) appeared to be less of a quantitative than of a structural nature.25 Two basic types of abnormality were described (heterotopic malformations): Absence of layer Pre-α, with only a few atypical neurons. Here the insular formations of Pre-α were also absent. Together with the upper portion of layer Pre-β, layer Pre-α had often the appearance of a “double row.