Huntingtin aggregates in human postmortem cerebral cortex and striatum from a presymptomatic case. Light micrographs are from the insular cortex (A) and dorsal striatum (B). Large numbers of EM48-immunoreactive aggregates of a wide variety of shapes and sizes are visible in cortex. All of these aggregates are in the neuropil. In contrast, striatal aggregates are exceedingly uncommon. Scale bar, 70 μm.