Examples of degenerating neurons in the right anterior cingulate cortex from an R6/2 transgenic mouse (A–C; 17 weeks old, 141 CAG repeats) and an HD patient (D–E; 11 years old, 100 CAG repeats). NII are present within all of these neurons. (Magnifications: A–C, ×1,250; D–E, ×2,250; F, ×1,000.)