Schedule of Events | Search Abstracts | Invited Symposia | Symposia | Rising Stars | Poster Sessions | Data Blitz

The Impact of Age on the Cortical Excitatory/Inhibitory Ratio Across the Lifespan

Poster Session A - Saturday, March 7, 2026, 3:00 – 5:00 pm PST, Fairview/Kitsilano Ballrooms

Attakias Mertens¹ (attakias.mertens@boystown.org), Derek Pavelka¹, Katrina Myers¹, Ryan Glesinger¹, Grace Ende¹, Jason John¹, Anna Coutant¹, Lucy Horne¹, Grant Garrison¹, Molly Voller¹, Kyla De Luca¹, Lan Volberding¹, Olivia Carusi¹, Hannah Okelberry¹, Hallie Johnson¹, Madelyn Willet¹, Jacob Oleson², Seth Bashford¹, Tony W. Wilson¹, Gaelle E. Doucet¹; ¹Boys Town National Research Hospital, ²University of Iowa

The balance of excitatory and inhibitory neural activity, the so-called E/I ratio, is thought to be critical for normal neural functioning. Prior human work has primarily focused on changes that occur during early development, with some reports linking changes in the E/I ratio to cognitive development. Despite this, variations in regional E/I ratios across the lifespan remain unknown. Herein, we aimed to address this using a large, lifespan sample of 883 healthy participants (F = 446, ages 8-87). The Schaefer-400 atlas was used to extract regional data from resting-state fMRI scans, which were then used to calculate the Hurst exponent (reflective of the inverse of E/I ratio) per region. Regions were then grouped according to network membership and generalized additive models were run using age as a predictor for network E/I ratio. A smoothed term for age was included in the models to assess nonlinearity. Results showed that each network exhibited increases in the E/I ratio with age. Specific similarities included three patterns with: 1) steeper increases in early development until ~30 years followed by a plateau throughout aging, seen in the somatomotor and limbic networks; 2 ) steeper increases until ~30 years followed by more gradual increases, seen in the visual and dorsal attention networks; and 3) more consistent increases, seen in the ventral attention, executive functioning, and default mode networks. While prior literature has focused on early development, these findings add novel insights into E/I ratio trajectories across the lifespan on a network level.

Topic Area: METHODS: Neuroimaging