Purkinje cells pathology in schizophrenia. A morphometric approach.

OBJECTIVES: Schizophrenia is a brain disorder that affects more than 21 million people worldwide. Ventricle enlargement and reduction in the volume of the temporal lobe overall and in medial temporal structures constitutes the main macroscopic findings, whilst synaptic and spinal changes as well as gliosis in the hippocampal formation, the prefrontal and the entorhinal cortex stand among cardinal microscopic findings in the schizophrenic brains. In recent years, accumulated evidence comes to light about the role of cerebellum in the pathophysiology of schizophrenia. MATERIALS AND METHODS: The present study is based on the morphological analysis and 3D neuronal reconstruction of the Purkinje cells from 10 schizophrenic brains and 10 normal controls. RESULTS: Significant morphological alterations such as loss of distal and terminal dendritic branches and decrease of the density of the dendritic spines constitute the main morphological findings found in the present study. CONCLUSIONS: The present findings may be added to accumulated evidence on macroscopic and microscopic pathology of the cerebellum in schizophrenia. Morphological alterations of Purkinje cells seem to be a central feature of neuropathology of schizophrenia, reflecting to impairment of neuronal connectivity and functionality, and related to motor and cognitive symptoms.

Dendritic and spinal alterations of neurons from Edinger-Westphal nucleus in Alzheimer's disease.

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder, causing a progressive decline of intellectual faculties, impairment of behavior and social performance, and impairment of speech eloquence, associated with various neurological manifestations based on a variable neuropathological background. Edinger-Westphal nucleus is a selective target of Alzheimer pathology early in the course of the disease. We attempted to determine the morphological alterations of the dendrites and the dendritic spines in Edinger-Westphal nucleus of 7 cases that fulfilled the diagnostic criteria for Alzheimer's disease. For the histological study, we applied (a) routine neuropathological techniques and (b) rapid Golgi method. We proceeded to 3D neuronal reconstruction for the estimation of dendritic and spinal changes in Alzheimer's disease. The morphological and morphometric analysis revealed a substantial neuronal loss and synaptic alterations in Edinger-Westphal nucleus in all the cases of Alzheimer's disease. Distal dendritic branches are prominently affected. The neuronal loss and alteration of the spines in Edinger-Westphal nucleus in Alzheimer's disease may be related to the exaggerated pupillary reaction to cholinergic antagonists. Furthermore, the vulnerability of distal branches to Alzheimer's disease might be related to neuroplasticity impairment.