Experimental model: change in the posterior fossa with surgically induced spina bifida aperta in mouse.

On the basis of experimental studies on mouse embryos in which spina bifida development of the brain ventricular system. Mouse embryos were exposed and surgically treated at gestation day 12 to produce spina bifida aperta, and operated embryos were cultured exo utero in the peritoneal cavity of the pregnant dam. Embryos were harvested at gestation day 14. Open neural tube defects resulted in 7 out of 10 embryos surviving surgery. Histological examination revealed that the sizes of ventricles in both the supra- and infratentorial compartments were greatly reduced in embryos with spina bifida aperta compared with control embryos. This result supports the hypothesis that leakage of cerebrospinal fluid through the opening of the caudal spine may be a major cause of brain abnormalities in patients with myelomeningocele.