Biology subjects

Musa, R.

Publications and source records attributed to Musa, R..

3 recordsLinked to original sources

bioRxiv2026

Sulcal pleating captures functional boundaries in human visual cortex

The folding of the cortical sheet within the human brain is related to its functional organization at the level of major sulci and gyri. Yet how smaller folding features hidden within the two thirds of cortex buried in sulci may relate to functional specialization of the cortex is not clear. Using human visual cortex as a test bed, we identify four hidden brain folds within the major sulcus which spans the dorsal visual stream and demonstrate that their spatial consistency across individuals is related to functional boundaries of visual cortex. In separate observation and replication participant groups, we combine structural and functional magnetic resonance imaging to show that the boundaries separating the visual field maps comprising the dorsal stream can be predicted from these hidden gyri with an accuracy matching current probabilistic definitions of visual cortex. By further demonstrating that these hidden gyri colocalize with cytoarchitectonic regions of the human brain, and that the variability in their shape and size correlates with individual differences in visual behaviors known to rely on the dorsal stream, we provide evidence for a novel neuroanatomic framework which suggests that mesoscale pleating patterns of the cortex within human sulci are functionally and behaviorally relevant.

neuroscience↗

bioRxiv2026

Protracted functional and structural reorganization of human prefrontal cortex supports lateralized category geometries

Despite being visually responsive, how prefrontal cortex represents visual categories across development and how this compares to posterior visual cortex remains unknown. Here, we show that ventrolateral prefrontal cortex (VLPFC) follows a fundamentally distinct developmental trajectory. Using functional and quantitative MRI in children and adults, we demonstrate that VLPFC exhibits reliable and structured category-selective responses in childhood that undergo prolonged reorganization into mature, hemisphere-specific representational geometries. Right VLPFC progressively organizes categories along an animate-inanimate axis, while left VLPFC consolidates a word-selective organization, a lateralization that strengthens across development. This restructuring contrasts sharply with ventral temporal cortex (VTC), which exhibits bilaterally organized, adult-like category structure in childhood. Critically, prefrontal representational structure emerges in alignment with conserved folding patterns of the precentral and inferior frontal sulci, suggesting that cortical anatomy provides a stable scaffold for the maturation of abstract representations. Quantitative MRI further reveals a non-linear trajectory of tissue development in right VLPFC, marked by adolescent reductions in macromolecular content and increased microstructural heterogeneity in adulthood, a pattern not observed in VTC. Together, these findings demonstrate that VLPFC undergoes prolonged, anatomically constrained refinement of category-related geometry characterized by hemisphere-specific taxonomies, rather than simply inheriting representational structure from sensory cortex. O_LIUnlike VTC (which shows early, bilateral, and stable category organization), VLPFC contains reliable, category-selective representations from childhood that undergo prolonged, hemisphere-specific developmental refinement rather than simple amplification C_LIO_LIRight VLPFC progressively consolidates an animate-inanimate representational axis across development, while left VLPFC establishes an early, stable word-selective organization consistent with language network maturation C_LIO_LIFunctional boundaries in VLPFC align with conserved intrasulcal folding motifs (plis de passage), demonstrating that anatomical scaffolding of category-selective responses extends beyond sensory cortex to prefrontal association cortex C_LIO_LIRight VLPFC undergoes adolescent pruning of cortical tissue microstructure diverging sharply from the continuous tissue proliferation observed in ventral temporal cortex C_LI

neuroscience↗

bioRxiv2024

Microstructural pruning in human prefrontal cortex scaffolds its functional reorganization across development

Neural representations in occipitotemporal cortex emerge during development in response to visual experience with ecological stimulus categories, such as faces or words. While similar category-selective representations have also been observed in the frontal lobe, how they emerge across development, whether current models of brain development extend to prefrontal cortex, and the extent to which such high-level representations are anatomically consistent across the lifespan is unknown. Through a combination of functional and quantitative MRI scans, we observe previously undescribed cortical folding patterns in human-specific inferior frontal cortex whose consistency reveals that childhood representations for visual object categories rearrange into stable adulthood patterns. This functional restructuring was distinct from occipitotemporal cortex where adult-like response patterns only scale in magnitude across development. The unique form of functional development in prefrontal cortex was accompanied by restructuring of cortical tissue properties: macromolecules are pruned across adolescence in prefrontal cortex while they proliferate in temporal cortex. These results suggest visual representations in distinct cortical lobes undergo distinct developmental trajectories, and that human-specific prefrontal cortex shows an especially protracted maturational process that necessitates late-stage tissue restructuring detectable in the living brain.

neuroscience↗