Abnormal Cerebral Vascularity in Mice with Histogenetic Disorders of the Cerebral Cortex and Postnatal Manifestation of Hydrocephalus

Abstract

Abstract Pregnant mice were exposed to 60Co gamma‐irradiation on day 13 of gestation, and the offspring after birth were examined in histological sections and microvascular specimens with India ink, in order to know the pathological changes leading to postnatal manifestation of hydrocephalus. The cerebrospinal fluid pressure was also measured.The offspring from birth to 12 days of age showed microcephaly or dysgenetic hydrocephaly with severely deranged cerebral cortical architecture. The microvascular specimens of these brains showed a deranged vascular pattern and poor vascular network in the brain mantle. Its severity was in proportion to that of the disorder of the cortical architecture. These brains were involved with blood congestion and perivascular hemorrhage in the periventricular white matter, and consequently with cystic degeneration and pseudoventricle formation, which changes became evident at 7 to 10 days of age. The cerebrospinal fluid pressure was not different from that of non‐treated control mice until 12 days of age. Around 14 days of age, the pressure began to increase concurrently with an external appearance of vaulted skull, indicating a transformation from degenerative ex vacuo type of hydrocephaly to progressive high‐pressure hydrocephalus.These results suggested that histogenetic disorders of the cerebral cortex caused abnormal vascular formation in the brain mantle and that the consequent intracerebral circulatory disturbance played a significant role for degenerative changes of the brain tissue and a failure of the cerebrospinal fluid dynamics at the time of brain growth spurt.