Fine structure of cortical tubers in tuberous sclerosis: a Golgi study

The fine structure of cerebral cortex, including cortical tubers, was studied in 3 patients with tuberous sclerosis. Tubers were found to consist of two predominant cell populations, astroglia and small multipolar (stellate) neurons. Both cell types tended to form aggregates within tubers, with glia more prominent in the subpial region. The stellate neurons of tubers had beaded or varicose dendrites with few dendritic spines. The findings suggest that neurons within tubers are an aberrant primitive cell type that fails to express the pyramidal cell shape and dendritic morphology that is characteristic of normal human neocortex. Cortex intervening between tubers had basically normal dendritic morphology. However, quantitative study showed a decrease in the length of dendritic branches of pyramidal neurons, as also observed in several other conditions manifested by mental retardation.