@misc{oai:repo.qst.go.jp:00070535,
 author = {Takai, Nobuhiko and Hirayama, Ryoichi and Matsumoto, Yoshitaka and Uzawa, Akiko and Ohba, Yoshihito and Nakamura, Saori and Furusawa, Yoshiya and 高井 伸彦 and 平山 亮一 and 松本 孔貴 and 鵜澤 玲子 and 古澤 佳也},
 month = {Sep},
 note = {The immature brain in the central nervous system is sensitive to ionizing radiation, and develops, at a later adult stage, disorders including mental retardation, attention deficit-hyperactivity disorder and cognitive dysfunction. The relationship between an impairment of spatial cognition and a merge of ectopic neurons in the dorsal hippocampus was investigated in adult rats that were prenatally exposed to X-ray irradiation. Adult rats receiving 1.5 Gy X-rays at embryonic day 15 (E15) showed significant learning disability in the water-maze task. According to the mean value of the swimming time, we categorized the irradiated adult rats into the following three groups: slightly damaged group, mildly damaged group and severely damaged group, but no significant difference in the brain weight was found between the three categorized groups. Ectopic neurons appearing at abnormal places were prominently observed in the dorsal hippocampus of the severely damaged group with a remarkable learning disturbance. Furthermore, to test whether the morphological deficiency of hippocampus in the severely damaged group affects hippocampal function, we examined neural activity in hippocampal slices prepared from prenatal exposure to X-rays in rats. The spatial pattern of neural activity toward and through CA1 of the severely damaged group was similar to that of the control rat, the response was distinctly weaker, producing less voltage spread and amplitude. These finding suggest that the cognitive dysfunction induced by prenatal exposure to X-ray irradiation may be attributable to ectopic neurons of the hippocampus and the reduction of hippocampal neural activity., 14th International Congress of Radiation Research (ICRR2011)},
 title = {Prenatal radiation-induced brain damage related to memory impairment},
 year = {2011}
}