The right postcentral gyrus medial segment is the medial portion of the postcentral gyrus within the parietal lobe, forming part of the primary somatosensory cortex (Brodmann areas 3, 1, and 2) that represents predominantly the contralateral lower limb and trunk in the somatotopic (“homuncular”) map. This region receives dense thalamocortical input from the ventral posterior nucleus of the thalamus and is critical for processing tactile, proprioceptive, and nociceptive information, contributing to conscious perception of body position and discriminative touch. Medially, it borders the marginal branch of the cingulate sulcus and is contiguous with paracentral lobule structures; functionally, it participates in sensorimotor integration, posture control, and coordination of complex movements that depend on accurate feedback from the leg and midline body. There is no direct link for this specific segment; see the related structure: Postcentral gyrus.
Genetic associations specific to the right postcentral gyrus medial segment as defined in the brainCOLOR Atlas have not been systematically cataloged, but converging GWAS and imaging‑genetics studies implicate this region as part of broader somatosensory and sensorimotor networks influenced by common variants. Large-scale cortical morphology GWAS (e.g., ENIGMA, UK Biobank) have identified loci near genes involved in neuronal development and synaptic function—such as microtubule- and axon-guidance–related genes—that affect cortical thickness and surface area in postcentral and adjacent parietal regions, though these effects are generally reported at the level of larger somatosensory or parietal parcels rather than the specific “right postcentral-gyrus-medial-segment.” Variants associated with neurodevelopmental and psychiatric disorders, including autism spectrum disorder, attention-deficit/hyperactivity disorder, and schizophrenia, as well as chronic pain and somatosensory phenotypes, have been linked to altered structure or function in the postcentral gyrus and neighboring primary somatosensory cortex, again typically at coarser parcellations. Polygenic scores for intelligence, educational attainment, and general cognitive ability show associations with cortical measures in sensorimotor and parietal regions that encompass the medial postcentral gyrus. Overall, current evidence supports a genetically influenced role for this region within somatosensory and higher-order integrative networks, but precise gene or variant associations tied uniquely to the right postcentral-gyrus-medial-segment in the brainCOLOR Atlas remain undifferentiated from broader postcentral and parietal cortex findings.
Overview generated by GPT-4o (2026).
Region ID: 66
Hemisphere: Right
Atlas: brainCOLOR
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Wali Sidiqyar*, Gaurav Rudravaram*, Elyssa M. McMaster, Trent M. Schwartz, Adam M. Saunders, Kurt G. Schilling, Bennett A. Landman "Introducing SPINS: A Shared Public Visualization Library of Neuroanatomical Structures." Medical Imaging with Deep Learning- short paper
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