Morphometric analysis in neurodegenerative disorders

The study of dendritic length and spine density has become a standard in the analysis of neuronal abnormalities since a considerable number of neurological diseases have their foundation in alterations in these structures. One of the best ways to study possible alterations in neuronal morphometry is the use of Golgi impregnation. Introduced more than a century ago, it is still the standard and state-of-the-art technique for visualization of neuronal architecture. We successfully applied the Golgi method to mouse, rat, monkey and human brain tissues for studying both the normal and abnormal morphology of neurons. We were able to discover subtle morphological alterations in neuronal dendrites and dendritic spines in different brain areas. Although Golgi preparations can be examined by electronic microscopy, we used light microscopy and Neurolucida reconstruction to quantitatively explore the relationship between total dendritic length and spine density in different types of neurons. This review summarizes the methodology used to quantify neuronal abnormalities and discusses the utility of these techniques in different models of neurodegeneration.