Cortical sensory aging is layer-specific

The segregation of processes into cortical layers is a convergent feature in animal evolution. However, how changes in the cortical layer architecture affect sensory system function and dysfunction remain unclear. We conducted layer-specific in-vivo 7T-MRI of the primary somatosensory cortex in younger and older adults and in an adult with congenital arm loss. Input layer IV is enlarged and more myelinated in older adults, and associated with extended sensory input signals, whereas with congenital arm loss, input layer IV contralateral to the missing limb is thinner. Age-related cortical thinning is driven by deep layers, and accompanied by altered functional modulation and behavioral readouts. Calcium imaging and histology in aging mice reveal increased sensory-evoked neuronal activity accompanied by increased parvalbumin expression as a potential inhibitory balance, with dynamic changes in layer-specific myelination across age. Using multimodal imaging, we demonstrate that middle and deep layers show specific vulnerability to aging across species.

Recommended citation: Liu, P., Doehler, J., Henschke, J.U., Northall, A., Serian, A., Loaiza-Carvajal, L.C., Budinger, E., Schwarzkopf, D. S., Speck, O., Pakan, J. M.P., and Kuehn, E. (2023). Cortical sensory aging is layer-specific. (p. 2023.12.01.567841). bioRxiv.
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