Altered somatodendritic structure of spiny neurons in caudate nucleus in aging humans
The complex of pathological changes occurring in the nigrostriate system is the main cause of impairement of motor function in Parkinson’s disease as well as in normal aging. The morphological substrate of functional impairement in the nigrostriate system is not only the loss of neurons, but also altered structure of neurons and their processes. The purpose of this study is to characterize the changes in the somatodendritic structure of Golgi-impregnated spiny neurons in the human caudate nucleus in aging. In old age group compared to middle age group, the morphological changes in spiny neurons included local changes in the thickness of the dendrites (appearance of thinned patches, varicosities, retraction bulbs), the occurrence of abnormally enlarged mushroom spines, filopodia, and two-fold decrease in the quantity of spines.