RBPMS and Alzheimer disease: We first assessed RGC numbers and distribution across ST subregions in a sub-cohort of patients with MCI (n = 6, mean age 89.5 ± 5.24 years, 3 females/3 males), AD (n = 10, mean age 86.0 ± 8.89 years, 4 females/6 males), and age- and sex-matched CN controls (n = 9, mean age 85.89 ± 11.85 years, 5 females/4 males), using a selective pan-RGC marker, ribonucleic acid binding protein with multiple splicing (RBPMS), for immunohistochemical (IHC) analysis.