PMID- 16483715
OWN - NLM
STAT- MEDLINE
DCOM- 20060630
LR  - 20071115
IS  - 0304-3940 (Print)
IS  - 0304-3940 (Linking)
VI  - 399
IP  - 1-2
DP  - 2006 May 15
TI  - Differential effects of x-irradiation on immature and mature hippocampal neurons 
      in vitro.
PG  - 57-60
AB  - X-irradiation to neuronal progenitor cells causes brain dysfunctions, such as a 
      mental retardation, in adulthood. However, little has been known about the degree 
      of radiosensitivity of neurons in the developmental stages at which they are most 
      vulnerable. In this study we compared the effect of irradiation on mature neurons 
      with that on immature neurons. Primary dissociated neuronal cultures were 
      prepared from fetal rat hippocampi of embryonic day 18. X-irradiations were 
      performed on the cultured cells at 7 or 21 days in vitro (DIV), and the cells 
      were fixed at 12 or 24 h after irradiation. Then the cells were stained with 
      4',6-diamidino-2-phenylindole (DAPI) or terminal deoxynucleotidyl 
      transferase-mediated dUTP nick end labeling (TUNEL). The apoptotic changes were 
      measured quantitatively by nuclear pyknosis and DNA fragmentation-both 
      characteristic morphological changes of apoptosis. Light microscopy with 
      differential interference contrast showed that 30 Gy of irradiation increased 
      cellular shrinkage in 7-DIV neurons but not in 21-DIV neurons. Quantitative 
      analysis using DAPI imaging showed that 30 Gy of irradiation significantly 
      enhanced pyknotic changes in 7-DIV neurons after 24 h. In contrast, this 
      irradiation did not enhance any pyknotic changes in 21-DIV neurons after 24 h. 
      Further TUNEL staining also showed that the irradiation did not enhance any DNA 
      fragmentation in nuclei of 21-DIV neurons after 24h. Hence, we showed that the 
      radiosensitivity of 21-DIV postmitotic neurons was significantly lower than that 
      of 7-DIV neurons, indicating that the susceptibility of such neurons depends on 
      their developmental stage.
FAU - Shirai, Katsuyuki
AU  - Shirai K
AD  - Department of Radiation Oncology, Gunma University Graduate School of Medicine, 
      Maebashi, Japan.
FAU - Mizui, Toshiyuki
AU  - Mizui T
FAU - Suzuki, Yoshiyuki
AU  - Suzuki Y
FAU - Kobayashi, Yasuhiko
AU  - Kobayashi Y
FAU - Nakano, Takashi
AU  - Nakano T
FAU - Shirao, Tomoaki
AU  - Shirao T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20060214
PL  - Ireland
TA  - Neurosci Lett
JT  - Neuroscience letters
JID - 7600130
SB  - IM
MH  - Animals
MH  - *Apoptosis
MH  - Cells, Cultured
MH  - DNA Fragmentation
MH  - Embryo, Mammalian/cytology
MH  - Hippocampus/*cytology
MH  - In Situ Nick-End Labeling
MH  - Mitosis
MH  - Neurons/cytology/*radiation effects
MH  - Rats
MH  - Rats, Wistar
MH  - Time Factors
EDAT- 2006/02/18 09:00
MHDA- 2006/07/01 09:00
CRDT- 2006/02/18 09:00
PHST- 2006/01/10 00:00 [received]
PHST- 2006/01/19 00:00 [revised]
PHST- 2006/01/22 00:00 [accepted]
PHST- 2006/02/18 09:00 [pubmed]
PHST- 2006/07/01 09:00 [medline]
PHST- 2006/02/18 09:00 [entrez]
AID - S0304-3940(06)00082-6 [pii]
AID - 10.1016/j.neulet.2006.01.048 [doi]
PST - ppublish
SO  - Neurosci Lett. 2006 May 15;399(1-2):57-60. doi: 10.1016/j.neulet.2006.01.048. 
      Epub 2006 Feb 14.