Work

Layer-specific vulnerability is a mechanism of topographic map aging

Year: 2023

Type: article

Abstract: Topographic maps form a critical feature of cortical organization, yet are poorly described with respect to their microstructure in the living aging brain. We acquired quantitative structural and functional 7T-MRI data from younger and older adults to characterize layer-wise topographic maps of the primary motor cortex (M1). Using parcellation-inspired techniques, we show that quantitative T1 and Quantitative Susceptibility Maps values of the hand, face, and foot areas differ significantly, revealing microstructurally distinct cortical fields in M1. We show that these fields are distinct in older adults and that myelin borders between them do not degenerate. We further show that the output layer 5 of M1 shows a particular vulnerability to age-related increased iron, while layer 5 and the superficial layer show increased diamagnetic substance, likely reflecting calcifications. Taken together, we provide a novel 3D model of M1 microstructure, where body parts form distinct structural units, but layers show specific vulnerability toward increased iron and calcium in older adults. Our findings have implications for understanding sensorimotor organization and aging, in addition to topographic disease spread.

Source: Neurobiology of Aging

DOI: 10.1016/j.neurobiolaging.2023.04.002

Authors: Alicia Northall, Juliane Doehler, Miriam Weber, Stefan Vielhaber, Stefanie Schreiber, Esther Kuehn

Institutions: Otto-von-Guericke-Universität Magdeburg, German Center for Neurodegenerative Diseases, Center for Behavioral Brain Sciences, Hertie Institute for Clinical Brain Research

Language: English

Topic: Advanced MRI Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,200