Piecing it together: Relationships between hippocampal subfields and cognitive impairment along the Alzheimer’s disease spectrum

Abstract Background The ability to form hippocampal‐dependent memories declines steadily in normal aging, and exponentially people with probable Alzheimer’s disease (AD). Correspondingly, the whole hippocampal formation follows same trajectories of decline. Critically, pathological changes distinguishable subfields related cognitive abilities are not well characterized in. Herein, we investigated how these subfield neuropsychological memory measures interact. Method Structural MRI data were collected from 29 biomarker‐confirmed individuals on AD spectrum (ADS) a comparison group 17 biomarker‐negative healthy adults examine interactions between subfield‐specific integrity markers. Cognitive assessments included Wechsler Logical Memory (WMS‐IV) Hopkins Verbal Learning (HVLT‐R) tests. High resolution volumes (CA1, CA2, CA3, dentate gyrus, subiculum) measured dedicated T2‐weighted slab hippocampi (TSE; 0.4 x 2.0 mm), co‐registered routine T1‐weighted (MPRAGE; 1.0 using automated segmentation (ASHS) software UPENN atlas consisting scans MCI older (Yushkevich et al., 2015). We performed cross‐sectional analysis relationship volume behavioral performance learning declarative memory. Relationships subtests probed multivariate models contrasting ADS controls, while controlling for age, education, intracranial volume. Result show that robustly predict WMS‐IV, but HVLT‐R, regardless group. Moreover, report unique contributions CA3 learning, subiculum recognition, CA2 recall. By dividing into ultra high‐resolution MRI, further elucidate their ADS‐related neurocognitive Conclusion Subfield‐specific atrophy human hippocampus may constitute sensitive measure decline patients spectrum. These results suggest specific selectively influence subprocesses memory, be used better model among