Reactive Gliosis in the Sensorimotor and Cingulate Cortex in Huntington’s Disease

Abstract

Huntington's disease is an autosomal dominant inherited and progressive neurodegenerative disease, characterized by prominent neurodegeneration in the basal ganglia and wide spread regions of the cerebral cortex including the primary motor, sensory and cingulate cortices. In a recent study by our laboratory have shown that the variability in symptomatology in Huntington's disease and striatal neuropathological grade correlate with the variable neuronal degeneration in the cerebral cortex. To determine whether the symptomatology in Huntington's disease and striatal neuropathology are also related to changes in glial cells, a study using manual counting and morphometric analysis was carried out in the sensory, motor and cingulate cortices in Huntington's disease cases. The results showed a significant increase of astrocytes and activated microglia and a significant shortening of microglial process in all three Huntington's disease cortical regions compared to neurologically normal cases. The results also showed a significant association between increase of astrocytes and activated microglia and striatal neuropathological grade but there was no association found between the changes in glial cells and the clinical symptomatology. The present study have also provided evidence that the increase of glial cells may be related to cortical neurodegeneration to some extent in the primary motor and cingulate cortices but not in the sensory cortex. These findings suggest that reactive astrogliosis and reactive microgliosis may occur in the primary motor, sensory and cingulate cortices in Huntington's disease and that these changes may have direct or indirect influence on the cortical and striatal neurodegeneration or vice versa.