"Surviving and Thriving": Evidence for Cortical GABA Stabilization in Cognitively-Intact Oldest-Old Adults

Britton, M. K.; Jensen, G.; Edden, R. A.; Puts, N. A.; Nolin, S. A.; Merritt, S. S.; Rezaei, R. F.; Forbes, M.; Johnson, K. J.; Bharadwaj, P.; Franchetti, M. K.; Raichlen, D. A.; Jessup, C. J.; Hishaw, G. A.; Van Etten, E. J.; Gudmundson, A. T.; Murali-Manohar, S.; Cowart, H.; Trouard, T. P.; Geldmacher, D. S.; Wadley, V. G.; Alperin, N.; Levin, B. E.; Rundek, T.; Visscher, K. M.; Woods, A. J.; Alexander, G. E.; Cohen, R. A.; Porges, E. C.

doi:10.1101/2023.09.08.556410

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bioRxiv · 10.1101/2023.09.08.556410

"Surviving and Thriving": Evidence for Cortical GABA Stabilization in Cognitively-Intact Oldest-Old Adults

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Abstract

Cortical GABA levels are reduced in older age; age-related differences in GABA may be associated with age-related cognitive change. The nature of age-related GABA differences in the highest-functioning stratum of the oldest-old (85+) population is not yet known. We extend our previously-reported Individual Participant Data Meta-Analysis of GABA levels (Porges et al., 2021) across the lifespan with four novel datasets sampling the cognitively-intact oldest-old. The slope of age-related GABA differences in cognitively-intact oldest-old adults flattens after roughly age 80. We interpret these findings as an effect of survivorship: inclusion in the study required intact cognition, and too great a reduction of GABA levels may not be compatible with neurophysiological function needed for intact cognition. This work contributes to a growing body of evidence suggesting that successful cognitive aging may require intact GABAergic function, as well as further characterizing successful aging amongst oldest-old adults.

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Britton, M. K., Jensen, G., Edden, R. A., Puts, N. A., Nolin, S. A., Merritt, S. S., Rezaei, R. F., Forbes, M., Johnson, K. J., Bharadwaj, P., Franchetti, M. K., Raichlen, D. A., Jessup, C. J., Hishaw, G. A., Van Etten, E. J., Gudmundson, A. T., Murali-Manohar, S., Cowart, H., Trouard, T. P., Geldmacher, D. S., Wadley, V. G., Alperin, N., Levin, B. E., Rundek, T., Visscher, K. M., Woods, A. J., Alexander, G. E., Cohen, R. A., Porges, E. C.. 2023-09-09. "Surviving and Thriving": Evidence for Cortical GABA Stabilization in Cognitively-Intact Oldest-Old Adults. https://doi.org/10.1101/2023.09.08.556410

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