J Korean Neurol Assoc.  2007 Aug;25(3):364-371.

Developmental Differences in NMDA Neurototoxicity and the Expression of NMDA Receptor 2B Subunit of Rat Hippocampus

• Youn YC
• Park TH
• Kwon OS
• Chae SA
• Lee CS

Abstract

BACKGROUND: The developing brain has a distinctive set of characteristics that make it have different susceptibility to excitotoxins. Using primary tissue cultures of rat hippocampus, we investigated the developmental susceptibility to N-methyl-D-aspartic acid (NMDA)-induced cell death at various days in vitro in relation to the appearance of Bcl-2 protein and NMDA receptor 2B subunit.
METHODS
Six, 12, and 18 days-in-vitro (DIV) hippocampal tissue cultures derived from 7-day-old Sprague-Dawley rat pups were used. Each group was treated with 100 micrometer NMDA in 5% CO2 incubator at 36 degrees C for 30 min. A western blot was then performed for the NeuN, Bcl-2 and NMDA receptor 2B subunit and propidium Iodide (PI) staining.
RESULTS
The NeuN and Bcl-2 were most highly expressed in 12 DIV tissues. The reductions of the NeuN and Bcl-2 protein expressions by NMDA were significant at the 12 and the 18 DIV tissues, but less at 6 DIV tissues (p<0.05). The PI staining showed that the area of fluorescence of the 7 DIV tissues after NMDA exposure was less than the DIV 13 and 19 tissues. Without NMDA treatment, the NMDA receptor 2B subunit protein expressions at the 6 DIV tissues were highest and decreased with maturation.
CONCLUSIONS
These results suggest that the immature tissues were more resistant to NMDA toxicity than the mature tissues, and further studies are needed to establish its relationship with the Bcl-2 protein and NMDA receptor 2B subunit.

Keyword

Hippocampus; Bcl2; NeuN protein; N-methyl-D-aspartate; NR2B protein

MeSH Terms

Animals
Blotting, Western
Brain
Cell Death
Fluorescence
Hippocampus*
Incubators
N-Methylaspartate*
Neurotoxins
Propidium
Rats*
Rats, Sprague-Dawley
N-Methylaspartate
Neurotoxins
Propidium