iiinova — where your digital self keeps evolving

Will Snyder

@willsnyder.bsky.social

Postdoctoral Fellow at the University of Pennsylvania and Children’s Hospital of Philadelphia. Curious about cortical folds. New on Bluesky!

Posts Replies Media

Will Snyder @willsnyder.bsky.social · 09/09/2026

Excited to share my poster (W94!) at Flux tomorrow! “Longitudinal stability of cortical folding during infancy provides a structural scaffold for early brain development” — would love to chat with those interested in brain structure-function and infant development /HBCD!

021

Will Snyder @willsnyder.bsky.social · 09/03/2026

(11/11) Also for anyone who may be curious about exploring sulcal complexity, feel free to check out our previous containerized toolkit to derive it from FreeSurfer outputs! figshare.com/articles/cod...

130

Will Snyder @willsnyder.bsky.social · 09/03/2026

(10/11) ++ Christopher Ching, Joan Han, Nancy Lee, @jmulle.bsky.social , Sarah Shultz, Sébastien Jacquemont, @carriebearden.bsky.social !

330

Will Snyder @willsnyder.bsky.social · 09/03/2026

(9/11) Very grateful to my wonderful mentors (Petra Vértes, Ed Bullmore, @bogglerapture.bsky.social) and amazing full team that made this work possible!!! ( @rshaf.bsky.social , Siyuan Liu, Elizabeth Levitis, Kuaikuai Duan, @kkumar.bsky.social, Charles Schleifer, Rune Boen, continued!..)

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

(8/11) Together, we nominate new and largely separable pathways of genetic influence on cortical folding, either by disrupting canalized neurodevelopmental programs for sulcation (rare variation) or by exerting distributed, pleiotropic influences on the developing cortical sheet (common variation)

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

(7/11) Annotating these genes' fetal expression, we found that sulcal complexity genes are enriched for distinct cellular and molecular developmental processes that span the entire radial axis of the fetal brain - suggesting no one tissue or cell type can be isolated in a model of cortical folding

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

(6/11) Our GWAS of sulcal complexity for each of 40 sulci across the cortex identified strong associations at specific loci and many candidate genes regulating sulcal complexity (50 in expanded set), with many genes implicated in fetal developmental processes that co-occur with sulcal formation

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

(5/11) Interestingly, these gradients align with a previous hypothesis that sharp gradients in arealization/cytoarchitecture may predispose locations for buckling or folding of the cortex during the rapid expansion of the fetal brain in the 2nd trimester

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

(4/11) We next examined common genetic variation in the UK Biobank. SNP-based heritability of sulcal complexity was not associated with above patterns of rare variation, but had striking alignment with cortical surface area -- with gradients of genetic correlations that "flip" sign across sulci

130

Will Snyder @willsnyder.bsky.social · 09/03/2026

(3/11) These rare variant effects on sulcal complexity reveal a unique neurodevelopmental signal not linked to area/thickness but instead converging on a spatial axis linked to the timing of prenatal sulcation. Rare variants seem to contract/expand how differentiated linear vs complex sulci present

121

Will Snyder @willsnyder.bsky.social · 09/03/2026

(2/11) First, across 9 diverse neurogenetic syndrome cohorts, we identified moderate-to-large effects (|standardized effect|>0.4) on sulcal complexity for many (14%) sulci, revealing visible changes in morphology -- such as atypical interruptions in the left STS for individuals with 16p11.2 deletion

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

(🧵1/11) We derived sulcal complexity -- a measure rooted in fetal sulcation, scoring folds from linear to complex shape -- in large cohorts with rare (n=615, 9 syndromes) and common (n~29,000, UKB) genetic variation, enabling us to systematically compare the genetic influences from each

120

Will Snyder @willsnyder.bsky.social · 09/03/2026

How may rare vs. common genetic variation separately influence how our brains – and their complex folding patterns – take shape? 🧬 🧠 Check out our new preprint (and final work from my PhD!) out now! ( + thread below) www.biorxiv.org/content/10.6...

biorxiv.org

1175