title: Symmetry and asymmetry in the human posterior thalamus. I. Cytoarchitectonic analysis in normal persons.
abstract: We parceled the posterior thalami of nine normal human brains according to cytoarchitectonic criteria, measured relevant nuclear volumes, and sought left-right asymmetries. We found that thalamic zones with multiple projections to the cerebral cortex, using the centromedian-parafascicular nucleus as a prototype, were mostly symmetric. This group includes the medial, lateral, and inferior pulvinar nuclei. Thalamic zones that project discretely to a few, clearly defined cortical receptor fields (using the medial geniculate nucleus [MG] as a prototype) closely reflected the asymmetry of the cortical fields to which they project. Hence, the MG showed a slight right-sided bias, and the lateralis posterior nucleus (related to the grossly asymmetric inferior parietal lobule) showed a significant leftsided bias in eight of the nine brains measured. This asymmetry may partially explain the apparent language specialization of the dominant thalamus.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000033:anatomy & histology; D002648:Child; D002675:Child, Preschool; D004292:Dominance, Cerebral; D005260:Female; D006801:Humans; D007223:Infant; D007802:Language / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000033:anatomy & histology; D013238:Stereotaxic Techniques; D013787:Thalamic Nuclei / Q000033:anatomy & histology; D013788:Thalamus / Q000033:anatomy & histology* / Q000502:physiology