The bilateral Left Cerebrum.Frontal Lobe.Precentral Gyrus.White Matter corresponds to the subcortical projection and association fibers underlying the precentral gyrus, the primary motor cortex region responsible for voluntary movement control. This white matter contains corticospinal and corticobulbar fibers that descend toward the brainstem and spinal cord, as well as intra-frontal and interhemispheric connections that integrate motor planning signals from premotor and supplementary motor areas. Functionally, this region is crucial for the transmission of motor commands from cortical neurons to lower motor centers, enabling fine control of contralateral skeletal musculature, especially distal limb movements. There is no direct link for this exact white-matter subdivision; see the related cortical region: Precentral gyrus.
The Left Cerebrum Frontal Lobe Precentral Gyrus White Matter, corresponding largely to primary motor cortex pathways, is implicated in several genetic and GWAS findings that involve motor control, neurodevelopment, and neurodegeneration rather than being a frequent primary target of large-scale imaging genetics studies. Variants in genes related to myelination and white matter integrity (such as those in oligodendrocyte and axonal guidance pathways, including NRG1, CNTN4, and genes within the major histocompatibility complex implicated in schizophrenia GWAS) have been associated with altered frontal white matter microstructure, with diffusion MRI studies reporting heritable variation in fractional anisotropy in precentral/frontal motor tracts. Large brain-structure GWAS (e.g., ENIGMA and UK Biobank–based studies) show that cortical surface area and thickness in frontal motor regions, including precentral gyrus, are moderately heritable and associated with common variants in loci such as those near HMGA2 and IGF1 that broadly influence brain size and cortical morphology, though these effects are not specific to the left precentral gyrus white matter. Motor-related disorders with strong genetic components—such as amyotrophic lateral sclerosis (e.g., C9orf72, SOD1, TARDBP, FUS), hereditary spastic paraplegia, and certain dystonias—demonstrate structural and microstructural abnormalities in precentral gyrus and its descending white matter tracts, suggesting that genetic risk variants for these conditions indirectly affect this region via degeneration or maladaptive development of corticospinal pathways. Additionally, polygenic risk for schizophrenia, bipolar disorder, and ADHD has been linked to frontal white matter changes overlapping motor and premotor areas, indicating pleiotropic genetic influences on frontal white matter architecture, although current evidence does not support a unique, region-specific set of genetic associations confined specifically to the bilateral Left Cerebrum.Frontal Lobe.Precentral Gyrus.White Matter as defined in the Talairach 1 mm atlas.
Overview generated by GPT-4o (2026).
Region ID: 685
Hemisphere: bilateral
Atlas: Talairach labels 1mm
Full Quality Version: Download MP4
Full Quality Version: Download MP4
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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