Exp Neurobiol 2007; 16(1): 19-26

Published online July 1, 2007

© The Korean Society for Brain and Neural Sciences

Effects of Neutron Radiation on Apoptotic Cell Death and Cell Proliferation in Dentate Gyrus of Rats

Sung-Eun Kim1, Mal-Soon Shin1, Yun-Hee Sung1, Hong Kim1, Jin-Oh Kang2, Baek-Vin Lim3, Yong-Seok Jee4 and Chang-Ju Kim1*

Departments of 1Physiology, 2Radiation Oncology, College of Medicine, Kyung Hee University, Seoul 130-701, 3Division of Leisure & Sports Sciences, Dongseo University, Busan 617-716, 4Department of Leisure Sports, College of Science, Hanseo University, Seosan 356-706, Korea

Correspondence to: *To whom correspondence should be addressed.
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Radiations are known to cause death of neuronal precursors and neuronal cells in the brains. Neutrons differ from photons in the mode of their interactions with tissues. Moreover, neutrons have a higher linear energy transfer and generate more dense ionization, resulting in inducing severe breakage of double-stranded DNA and generation of more free radicals than photons. In the present study, we investigated the effects of fast neutron radiation on apoptotic neuronal cell death and cell proliferation in the hippocampal dentate gyrus of the rats. For this study, immunohistochemistry for caspase-3 and 5-bromo-2-deoxyuridine (BrdU), and terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) staining were performed. In the present results, high-dose of fast neutron radiation (1 Gy) increased apoptotic neuronal cell death and suppressed cell proliferation in the dentate gyrus. The present study shows that high-dose of fast neutron radiation may exert negative effects on the cognitive functions, especially hippocampal-dependent learning tasks by enhancing apoptosis and by suppressing cell proliferation of hippocampal neuronal cells.

Keywords: fast neutron radiation, dentate gyrus, apoptosis, cell proliferation