The Neuropathology Core (Core D) of the Johns Hopkins Alzheimer's Disease Research Center (ADRC) has two overarching goals, one related to the analysis and distribution of brain tissue and other specimens from subjects in the ADRC, and the other related to the analysis of genetically engineered mouse models by investigators associated with the ADRC. The specific aims of Core D are as follows: (1) to arrange and perform autopsies on clinically well-characterized subjects enrolled through the JHMI ADRC and assist with consensus diagnoses on subjects associated with the ADRC (comprised of the Clinic Cohort and the BLSA Cohort). (2) to accession and store optimally prepared tissues from the autopsies and to make these specimens available to investigators associated with the ADRC and at other collaborating institutions. (3) to accession and store samples of biological fluids and DNA obtained pre- and postmortem from subjects in the ADRC. (4) to facilitate APOE genotyping on participants in the ADRC. (5) to support the assessment of genetically engineered mouse models relevant to Alzheimer's disease (AD) and related disorders, (6) to collaborate with the medical and research community outside of Johns Hopkins by providing assistance with postmortem diagnoses of AD and other types of dementia, and (7) to train basic investigators and clinical neuroscientists in the morphological and diagnostic concepts relevant to AD, to other types of dementias and neurodegenerative disorders.