Neuroprotective effects of mild hypoxia in organotypic hippocampal slice cultures.
OBJECTIVE
The aim of this study was to investigate the potential effects of mild hypoxia in the mature and immature brain.


METHODS
We prepared organotypic slice cultures of the hippocampus and used hippocampal tissue cultures at 7 and 14 days in vitro (DIV) to represent the immature and mature brain, respectively. Tissue cultures were exposed to 10% oxygen for 60 minutes. Twenty-four hours after this hypoxic insult, propidium iodide fluorescence images were obtained, and the damaged areas in the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis.


RESULTS
In the 7-DIV group compared to control tissue, hypoxia-exposed tissue showed decreased damage in two regions (CA1: 5.59%±2.99% vs. 4.80%±1.37%, P=0.900; DG: 33.88%±12.53% vs. 15.98%±2.37%, P=0.166), but this decrease was not statistically significant. In the 14-DIV group, hypoxia-exposed tissue showed decreased damage compared to control tissues; this decrease was not significant in the CA3 (24.51%±6.05% vs. 18.31%±3.28%, P=0.373) or DG (15.72%±3.47% vs. 9.91%±2.11%, P=0.134), but was significant in the CA1 (50.91%±5.90% vs. 32.30%±3.34%, P=0.004).


CONCLUSIONS
Although only CA1 tissues cultured for 14 DIV showed significantly less damage after exposure to hypoxia, the other tissues examined in this study showed a tendency towards less damage after hypoxic exposure. Therefore, mild hypoxia might play a protective role in the brain.
Department of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
Seh Hyun
SH
Kim
Department of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
Woo Soon
WS
Lee
Department of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
Na Mi
NM
Lee
Department of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
Soo Ahn
SA
Chae
Department of Pediatrics, Chung-Ang University College of Medicine, Seoul, Korea.
Sin Weon
SW
Yun
Brain; Hippocampus; Hypoxia