title: Enhanced expression of microtubule-associated protein 2 in large neurons of cortical dysplasia.
abstract: To evaluate neuronal cytoarchitectural changes in cortical dysplasia, we examined microtubule-associated protein 2 (MAP2) expression in surgically resected specimens obtained from 20 patients (age range, 3 months to 10 years) treated for intractable epilepsy. Large neurons were investigated in the specimens from all patients and showed significantly strong immunoreactivity with antibodies against MAP2 in the perikaryon and proximal portion of their processes. In situ hybridization with MAP2 antitense riboprobe showed increased hybridization signal intensities in the large neurons, which correlated with the pattern of immunoreactivity for MAP2. We conclude that MAP2 is strongly expressed in the large neurons in cortical dysplasia. The results of preliminary immunoblotting in 1 patient with focal cortical dysplasia showed that the low-molecular-weight form of MAP2 (MAP2c) was strongly expressed in the dysplastic cortex, suggesting that MAP2c may be a major component contributing to the increased expression of MAP2 in the large neurons of cortical dysplasia. Since it has been suggested that MAP2 plays a crucial role in the branching and remodeling of neuronal processes, increased expression of MAP2 may reflect activated plasticity of the large neurons in cortical dysplasia.
authors.affiliation: Department of Pathology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Yamanouchi
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: V
authors.initials: V
authors.lastname: Jay
authors.forename: L E
authors.initials: LE
authors.lastname: Becker
mesh_terms: D001483:Base Sequence; D002540:Cerebral Cortex / Q000737:chemistry* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D018076:DNA, Complementary / Q000032:analysis; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D006965:Hyperplasia; D015151:Immunoblotting; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007223:Infant; D008297:Male; D008869:Microtubule-Associated Proteins / Q000032:analysis* / Q000235:genetics; D008969:Molecular Sequence Data; D012189:Retrospective Studies; D015854:Up-Regulation
chemical_list: D018076:DNA, Complementary; D008869:Microtubule-Associated Proteins