EXPRESS: GABAA receptor α subunit distribution is congruent with functional anatomical areas in the human cortex

We recently published putative in vivo maps of GABAA receptor subtypes-α1/α3, α2, and α5. Here we tested how these maps align with functional anatomical cortical areas and large-scale functional networks.

Cortical α subunit maps were projected to the symmetric fs_LR template and compared with the Human Connectome Project multi‑modal parcellation. Congruence was assessed by visual inspection, within‑parcel variability, and the distance‑controlled boundary coefficient (DCBC) with spin‑permutation null models. Subunit profiles were summarized per cortical area and related to functional networks.

Inspection revealed conspicuous congruence between α -subunit distributions and areal boundaries. α1/α3 subunits predominated in primary sensory/motor areas, α2 peaked in neighboring secondary areas and α5 was concentrated in cingulo-opercular and insular areas. Within‑parcel variability was low, and congruence was supported by a positive, significant DCBC (0.1065, p-spin=0.0006) exceeding the random parcellation. Large‑scale networks showed characteristic subunit combinations: functionally "narrow" networks were subunit-predominant, while associative networks clustered around mixed patterns away from extremes.

Cortical GABAA receptor α subunit distributions align with multimodal areas and display network‑specific profiles, linking inhibitory chemiarchitectonics to cortical organization. The present analysis supports integration of molecular with structural and functional imaging for extended understanding of human brain function.

gov: NCT00681720 and NCT00681746.