Stephen F Smagula1, Helmet T Karim2, Anusha Rangarajan3, Fernando Pasquini Santos4, Sossena C Wood3, Tales Santini3, John M Jakicic5, Charles F Reynolds2, Judy L Cameron2, Abbe N Vallejo6, Meryl A Butters2, Caterina Rosano7, Tamer S Ibrahim3, Kirk I Erickson8, Howard J Aizenstein2. 1. Department of Psychiatry, Western Psychiatric Institute and Clinic of University of Pittsburgh Medical Center, Pittsburgh, PA; Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA. Electronic address: sfs26@pitt.edu. 2. Department of Psychiatry, Western Psychiatric Institute and Clinic of University of Pittsburgh Medical Center, Pittsburgh, PA. 3. Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA. 4. Faculty of Electrical Engineering, Federal University of Uberlândia, Uberlândia, Brazil. 5. Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA. 6. Department of Pediatrics and Immunology, University of Pittsburgh, Pittsburgh, PA. 7. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA. 8. Department of Psychology, University of Pittsburgh, Pittsburgh, PA.
Abstract
OBJECTIVES: Hippocampal hyperactivation marks preclinical dementia pathophysiology, potentially due to differences in the connectivity of specific medial temporal lobe structures. Our aims were to characterize the resting-state functional connectivity of medial temporal lobe sub-structures in older adults, and evaluate whether specific substructural (rather than global) functional connectivity relates to memory function. METHODS: In 15 adults (mean age: 69 years), we evaluated the resting state functional connectivity of medial temporal lobe substructures: dentate/Cornu Ammonis (CA) 4, CA1, CA2/3, subiculum, the molecular layer, entorhinal cortex, and parahippocampus. We used 7-Tesla susceptibility weighted imaging and magnetization-prepared rapid gradient echo sequences to segment substructures of the hippocampus, which were used as structural seeds for examining functional connectivity in a resting BOLD sequence. We then assessed correlations between functional connectivity with memory performance (short and long delay free recall on the California Verbal Learning Test [CVLT]). RESULTS: All the seed regions had significant connectivity within the temporal lobe (including the fusiform, temporal, and lingual gyri). The left CA1 was the only seed with significant functional connectivity to the amygdala. The left entorhinal cortex was the only seed to have significant functional connectivity with frontal cortex (anterior cingulate and superior frontal gyrus). Only higher left dentate-left lingual connectivity was associated with poorer CVLT performance (Spearman r = -0.81, p = 0.0003, Benjamini-Hochberg false discovery rate: 0.01) after multiple comparison correction. CONCLUSIONS: Rather than global hyper-connectivity of the medial temporal lobe, left dentate-lingual connectivity may provide a specific assay of medial temporal lobe hyper-connectivity relevant to memory in aging.
OBJECTIVES: Hippocampal hyperactivation marks preclinical dementia pathophysiology, potentially due to differences in the connectivity of specific medial temporal lobe structures. Our aims were to characterize the resting-state functional connectivity of medial temporal lobe sub-structures in older adults, and evaluate whether specific substructural (rather than global) functional connectivity relates to memory function. METHODS: In 15 adults (mean age: 69 years), we evaluated the resting state functional connectivity of medial temporal lobe substructures: dentate/Cornu Ammonis (CA) 4, CA1, CA2/3, subiculum, the molecular layer, entorhinal cortex, and parahippocampus. We used 7-Tesla susceptibility weighted imaging and magnetization-prepared rapid gradient echo sequences to segment substructures of the hippocampus, which were used as structural seeds for examining functional connectivity in a resting BOLD sequence. We then assessed correlations between functional connectivity with memory performance (short and long delay free recall on the California Verbal Learning Test [CVLT]). RESULTS: All the seed regions had significant connectivity within the temporal lobe (including the fusiform, temporal, and lingual gyri). The left CA1 was the only seed with significant functional connectivity to the amygdala. The left entorhinal cortex was the only seed to have significant functional connectivity with frontal cortex (anterior cingulate and superior frontal gyrus). Only higher left dentate-left lingual connectivity was associated with poorer CVLT performance (Spearman r = -0.81, p = 0.0003, Benjamini-Hochberg false discovery rate: 0.01) after multiple comparison correction. CONCLUSIONS: Rather than global hyper-connectivity of the medial temporal lobe, left dentate-lingual connectivity may provide a specific assay of medial temporal lobe hyper-connectivity relevant to memory in aging.
Authors: Henry W Chase; Mareike Clos; Sofia Dibble; Peter Fox; Anthony A Grace; Mary L Phillips; Simon B Eickhoff Journal: Neuroimage Date: 2015-03-14 Impact factor: 6.556
Authors: Mark E Whiting; Joseph Mettenburg; Enrico M Novelli; Tales Santini; Tiago Martins; Tamer S Ibrahim; Philip R LeDuc; Jonathan Cagan Journal: J Eng Sci Med Diagn Ther Date: 2022-02-23
Authors: Xintong Zuo; Jie Zhuang; Nan-Kuei Chen; Scott Cousins; Priscila Cunha; Eleonora M Lad; David J Madden; Guy Potter; Heather E Whitson Journal: Neurobiol Aging Date: 2020-07-30 Impact factor: 5.133
Authors: Tales Santini; Minseok Koo; Nadim Farhat; Vinicius P Campos; Salem Alkhateeb; Marcelo A C Vieira; Meryl A Butters; Caterina Rosano; Howard J Aizenstein; Joseph Mettenburg; Enrico M Novelli; Tamer S Ibrahim Journal: Neuroimage Clin Date: 2021-04-03 Impact factor: 4.881