Experimentally induced cranial meningocele and cerebral microgyria

Teratological study on microgyra is rare, and its morphogenesis is still on dispute. Microgyra associated with cranial meningocele and progressive hydrocephalus were induced in rat siblings by administration of 10 mg/kg.bw of n-methyl n-nitrosourea (MNU) to rat dams on day 9 of gestation. Microgyra were closely similar to human cases. They were formed during progressive stage of hydrocephalus, when the expansion of cranial meningocele was proceeding. This stage was in accord with migratory and postmigratory phase of neuroblasts. The results of this study suggest that the formation of microgyra may be related to the cortical laminar destruction during this critical period of differentiating brain.