The Neuropathology (NP) Core provides gold-standard neuropathologic diagnoses for the USC ADRC participants and banks fresh and frozen nervous system tissue for distribution to support ADRD researchers inside and outside of USC. The NP Core houses tissue from >1,100 cases. Tissue provided by the Core is unique among ADRC repositories in the exceptional variety of tissue (e.g., eyes, spinal cord) available. Each case is reviewed independently by the two Core leaders (Drs. Annie Hiniker and Debra Hawes, both board-certified neuropathologists) who apply NACC 11 standards for diagnosis and then re-review together to reach consensus if needed. Each case will be stained for H&E, phospho-tau (AT8), beta-Amyloid (4G8), α-synuclein, and TDP43. Diagnostic stains available and utilized as needed are AT8, RD3, and RD4 for tau species, 4G8 for Abeta, anti-alpha-synuclein for Lewy bodies, Iba-1 for macrophages, GFAP for gliosis, and neuronal markers including NeuN and NSE. Drs. Hiniker and Hawes are expert in developing and implementing new immunostains and new markers will be added as appropriate for refined diagnoses and research applications. Under the leadership of Dr. Hiniker and Dr. Michael Bienkowski, an expert in digital pathology, the Core will collaborate with the DMSC Core to develop an accessible digital pathology library of our autopsy cohort of >1,100 cases that will be ultimately integrated with genetic and biomarker data from the Biomarker Core. The NP Core contributes to our Center’s studies of the effects of APOE genotype on ADRD, particularly focusing on the relationship of APOE genotype to vascular pathology and perivascular inflammation. The Core also measure the detailed contributions of APOE genotype to pathology and cognitive impairment in collaboration with the Clinical Core. Finally, NP Core faculty support mentoring and training in ADRD and collaborate with the REC to educate students, residents and fellows in the pathologic diagnosis of ADRD.