Morphological alterations of the pyramidal and stellate cells of the visual cortex in schizophrenia.

Schizophrenia is a severe brain disorder characterized by certain types of delusion, hallucination and thought disorder. Studies have revealed impaired synaptic plasticity and reduced gamma-aminobutyric acid levels of the visual cortex in patients with schizophrenia. While previous work established a critical role for interneurons and cortical connectivity in the generation of hallucinations, the present study set out to examine the morphology of pyramidal cells and interneurons from layers 3 and 4 in the primary visual cortex from schizophrenic brains and to identify any dendritic and spinal alterations in comparison to normal control brains. The morphological and morphometric changes of the pyramidal cells and the interneurons of the visual cortices of 10 brains obtained from patients with schizophrenia, in comparison to 10 age-matched controls, were studied using the Golgi method and 3D neuronal reconstruction techniques. Analysis using the Golgi impregnation technique revealed a significant loss of distal dendritic segments, tortuous branches and varicosities and an overall restriction of the dendritic field in the brains of schizophrenic patients in both pyramidal cells and in aspiny interneurons. The present results may explain certain clinical phenomena associated with the visual cortex usually encountered in schizophrenia.

A Voxel-Wise Meta-Analysis on the Cerebellum in Essential Tremor.

Background and Objectives: Essential tremor is a chronic progressive neurological condition. The clinical presentation of essential tremor is heterogeneous and includes involuntary tremor on hands or arms and progressively on head, jaw, and voice. More extensive and complex symptoms may also be noticed in several patients. Many studies have been carried out to identify biomarkers to help the diagnosis, however, all the efforts have not shown any substantial results yet. Materials and Methods: Here, we aimed to perform a voxel-based meta-analysis using a dedicated cerebellar mask to clarify whether the results from the previous studies are robust and have any clinical significance. We included studies with a total of 377 essential tremor patients and 338 healthy control individuals. Results: A significant regional decrease in the volume of the gray matter was detected in the right cerebellar hemispheric lobule IV/V, and in the cerebellar vermic lobule IV/V. Conclusions: This is the first study focused on the cerebellum and using a specific cerebellar mask, which increases the sensitivity. It showed regional statistically significant changes that could not be seen in the whole-brain analysis.

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.

Spinal Alterations of Reil Insula in Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease that involves numerous cellular and biochemical mechanisms resulting in synaptic alterations and extensive neuronal loss. It is primarily characterized by impairment of memory, associated frequently with mood disorders. Continuous studies have shown that insula may be an important target of AD, but neuropathological alterations have not been described extensively. In the present study, we attempted to describe the morphometric and morphological changes of the spines of Reil insula in AD in comparison with normal aging using a silver impregnation technique. We classified spines into 3 types: (1) long neck, (2) short stubby, and (3) other types; and we measured and correlated the length of them in normal controls and in individuals with AD using ImageJ application. Statistical analysis was based on the Student t test on the basis of 360 cells in SPSS v.17.0, and significance was taken as P < .05.

Age-related dendritic and spinal alterations of pyramidal cells of the human visual cortex.

INTRODUCTION: Normal aging is characterized by deterioration of visual abilities, affecting mainly visual acuity, contrast and wavelength sensitivity. In the present study we attempted to describe the morphological and morphometric alterations of the dendrites and the dendritic spines of the pyramidal cells of the visual cortex during normal aging, in order to approach the visual impairment of aged individuals from a neuropathological point of view. MATERIAL AND METHODS: We studied the visual cortex in 20 brains using the Golgi technique. RESULTS: In pyramidal cells, which represent the majority of cortical neurons, age-related pathology can be observed in cell somata as well as, most importantly, in dendrite number and morphology. The apical dendrites of some pyramidal cells are distorted and tortuous. Horizontal dendritic arborization is also severely decreased. These alterations were more prominent in the corticocortical pyramidal neurons of the 5th layer. CONCLUSIONS: The morphological and morphometric assessment of the dendrites and the dendritic spines in the visual cortex in normal aging revealed substantial alterations of the dendritic arborization and marked loss of the dendritic spines, which may be related to visual impairment even in normal aging.

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.

Dendritic and spinal pathology of the Purkinje cells from the human cerebellar vermis in Alzheimer's disease.

BACKGROUND: Alzheimer's disease constitutes one of the main causes of dementia. It is clinically characterized by memory impairment, deterioration of intellectual faculties and loss of professional skills. Furthermore changes in equilibrium and limb coordination are clinically demonstrable in persons with Alzheimer's disease. In the present study we tried to figure out possible changes of the Purkinje cells in Alzheimer's disease brains. SUBJECTS AND METHODS: We studied the Purkinje cells from the vermis of the cerebellum in 5 Alzheimer' disease brains Golgi technique. RESULTS: In the Purkinje cells from the inferior surface of the cerebellar hemispheres severe dendritic and spinal pathology consisting of loss of distal dendritic segments and alterations of dendritic spine morphology can be noticed in Alzheimer's disease brains. CONCLUSIONS: The morphological and morphometric estimation of the dendrites and the dendritic spines of the Purkinje cells from the inferior surface of the cerebellar hemispheres in Alzheimer's disease brains revealed substantial alterations of the dendritic arborization and marked loss of the dendritic spines, which may be related to cognitive impairment and motor deficits in Alzheimer's disease.

Dendritic, axonal, and spinal pathology of the Purkinje cells and the neurons of the dentate nucleus after long-term phenytoin administration: a case report.

Phenytoin is a commonly prescribed anticonvulsant drug; however, there is evidence that long-term administration is related to cerebellar ataxia, cerebellar atrophy, loss of Purkinje cells, and hyperplasia of Bergman glia cells. The aim of the present study was to detect and describe any possible alterations of the Purkinje cells, and neurons of the dentate nucleus, as those can be seen with the use of silver impregnation techniques, such as Golgi and Nauta method. The study was performed on a 7-year-old boy who was under phenytoin treatment for more than 3.5 years and had clinical manifestations of cerebellar ataxia. Golgi silver impregnation technique revealed substantial loss of dendritic spines and tertiary dendritic branches, both on the Purkinje cells and the neurons of the dentate nucleus, whereas the Nauta method demonstrated swollen and degenerated axons of Purkinje cells.

Dendritic and spinal alterations of the spiny stellate cells of the human visual cortex during normal aging.

The visual cortex undergoes age related changes that have been studied mainly in rats Maccaca Mulata, and human beings. Despite the fact that there is no extensive neuronal loss in aged brains, a lot of important pathological changes are found in the morphology of the neurons. The present study describes the morphological alterations of the spiny stel-late cells of the human primary visual cortex during normal aging, using Golgi method, Golgi-Nissl staining and Nissl staining. Two types of spiny stellate cells have been studied. the first one located at layer 4Cß and the second one located at layer 4Cß. Even if some spiny stel-late cells retain high number of primary dendrites in the aged group there seems to be important spine loss, and extensive dendrite pathology. Age-related changes were more significant in spiny stellate cells of layer 4Cß. Dendritic and spinal alterations described in the present study could explain the decline in visual functions during normal aging.