Figure 2.

HD is characterized by abnormal protein deposits containing mutant huntingtin. (A) Huntingtin immunoreactivity in neuronal intranuclear inclusions (hNIIs) and dystrophic neurites in HD brain. Cortex of a juvenile patient shows numerous hNIIs prominently stained. (B and C) Cortical pyramidal neurons in a different juvenile patient shown with Nomarski optics contain one (B) and two (C) hNIIs. A–C, Adapted with permission from (DiFiglia et al. 1997). The nucleolus in each cell is unlabeled. (D–E) Huntingtin aggregates in human postmortem cerebral cortex and striatum from a presymptomatic case. Light micrographs are from the insular cortex (D) and dorsal striatum (E). 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. D–E, Adapted with permission from (Gutekunst et al. 1999).