postcentral-gyrus

Overview

The Left postcentral gyrus is the left-hemispheric portion of the primary somatosensory cortex (Brodmann areas 3, 1, and 2), located immediately posterior to the central sulcus in the parietal lobe. It receives dense thalamocortical input from the ventral posterior nuclei of the thalamus and is topographically organized into a somatotopic map (the sensory homunculus), with lower limbs represented medially and facial structures laterally. This region is crucial for the conscious perception and discrimination of tactile stimuli, including touch, pressure, vibration, temperature, and proprioceptive information from the contralateral side of the body. Damage to the left postcentral gyrus can result in contralateral sensory deficits such as impaired two-point discrimination, astereognosis, and altered body schema, and may also influence higher-order sensorimotor integration with frontal motor regions. Postcentral gyrus

The left postcentral gyrus, corresponding primarily to primary somatosensory cortex, shows genetic associations in imaging GWAS with variants near genes implicated in cortical structure and neurodevelopment, including microtubule- and synapse-related loci (e.g., in ENIGMA and UK Biobank cortical thickness/surface area studies), though findings are often shared across multiple cortical regions rather than being uniquely specific. SNP-based heritability estimates indicate moderate heritability for its thickness and surface area, with polygenic influences overlapping those for global cortical measures, intracranial volume, and general cognitive ability. Several neurodevelopmental and neuropsychiatric disorder GWAS—most notably for autism spectrum disorder, ADHD, and schizophrenia—report structural or functional alterations in the left postcentral gyrus that co-localize with risk loci affecting cortical development, sensory processing, and synaptic plasticity, although direct, region-specific gene–brain associations remain sparse. In addition, genes and loci identified in GWAS of handedness, motor and sensory traits (e.g., pain sensitivity, tactile perception), and general intelligence have been linked to structural or functional variability in somatosensory and adjacent motor areas that include the left postcentral gyrus, suggesting that genetic influences on sensorimotor integration and higher-order cognition partly converge in this region.

Overview generated by GPT-4o (2026).

Region ID: 93
Hemisphere: Left
Atlas: brainCOLOR

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