RESUMEN
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.
Asunto(s)
Envejecimiento/patología , Espinas Dendríticas/patología , Células Piramidales/patología , Corteza Visual/patología , Adulto , Anciano , Anciano de 80 o más Años , Dendritas/patología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
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.
Asunto(s)
Enfermedad de Alzheimer/patología , Espinas Dendríticas , Células de Purkinje , Anciano , Anciano de 80 o más Años , Espinas Dendríticas/patología , Espinas Dendríticas/ultraestructura , Femenino , Humanos , Masculino , Células de Purkinje/patología , Células de Purkinje/ultraestructuraRESUMEN
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.
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Anticonvulsivantes/uso terapéutico , Núcleos Cerebelosos/efectos de los fármacos , Epilepsia Tónico-Clónica/tratamiento farmacológico , Fenitoína/uso terapéutico , Células de Purkinje/efectos de los fármacos , Anticonvulsivantes/farmacología , Axones/efectos de los fármacos , Axones/patología , Núcleos Cerebelosos/patología , Niño , Dendritas/efectos de los fármacos , Dendritas/patología , Espinas Dendríticas/efectos de los fármacos , Espinas Dendríticas/patología , Epilepsia Tónico-Clónica/patología , Humanos , Masculino , Fenitoína/farmacología , Células de Purkinje/patologíaRESUMEN
Alzheimer's disease is a neurodegenerative disorder characterized by progressive decline in memory, loss of professional skills, impairment of judgement and behavior, and decline in social performances. In terms of neuropathology, the morphological hallmarks of the disease are the accumulation of alpha-beta peptide and the neurofibrillary degeneration, associated with synaptic alterations, involving mostly the dendritic spines. This study is based on the morphological analysis of 10 brains, 5 of which were obtained from patients who suffered from Alzheimer's disease and 5 from nondemented senile individuals used as control group. The segments taken in major from the occipital lobe were studied with the use of Golgi method, as well as Gallyas' and Bielschowski' s staining methods. In most of the pyramidal cells in the affected brains, there seems to be important spine loss and extensive dendrite pathology. Apical dendrites are distorted and tortuous. Horizontal dendritic arborization is severely decreased leading to an amputated, bell-shaped cell soma. Senile plaques have been often revealed, and neurofibrillary changes have also been noticed.
Asunto(s)
Enfermedad de Alzheimer/patología , Dendritas/patología , Médula Espinal/patología , Corteza Visual/patología , Anciano , Anciano de 80 o más Años , Recuento de Células , Tamaño de la Célula , Femenino , Adhesiones Focales/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Ovillos Neurofibrilares/patología , Neuronas/patología , Células Piramidales/patología , Tractos Piramidales/patología , Tinción con Nitrato de PlataRESUMEN
Alzheimer's disease is a neurodegenerative disorder, characterized by progressive decline in memory and in social performance. The morphological hallmarks of the disease are neuronal loss, loss of dendritic spines, neurofibrillary degeneration and neuritic plaques mainly in the hippocampus and the cortex of the cerebral hemispheres. This study is based on the morphological analysis of the cerebellar cortices of eight brains, 4 patients suffered from Alzheimer's disease and 4 normal controls, by Golgi method, as well as Nissl, Gallyas', Bielschowsky's, Methenamine Silver staining and Congo red methods. Although typical neuritic plaques were not seen in the cerebellar cortex and the diffuse plaques found in the cerebellum in far smaller proportion than plaques in the prefrontal and parietal cortices of the same cases, Golgi impregnation technique revealed a loss of Purkinje cells and a marked decrease in the density of dendritic arborization.