Figure 7.

Neuropathological findings in the locus coeruleus of a 45–50 year old woman heterozygous for the A431E mutation in PSEN1, a 35–40 year old man homozygous for the A431E mutation in PSEN1, and a normal control (45–50 year old). Hematoxylin and Eosin (H&E) staining shows profound drop-out of neurons in the PSEN1 mutation carriers compared to control. Neurons within carriers lack neuromelanin and show loss of pigment; whereas, neurons within control show robust pigmentation and neuromelanin expression. Immunostained slides with anti-tau (AT8) antibodies using red chromagen demonstrate neurofibrillary tangles within neurons and the presence of many tau positive threads in PSEN1 mutation carriers with only a very rare single neurofibrillary tangle observed in normal control (lower portion of image).