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August 1996
Volume 60 |
Number 8
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| Figure 1 |
Excitotoxicity in the Brain
Hypoxia/ischemia results in excessive amounts of extracellular
excitatory amino acids (EAAs), glutamate (GLU) and aspartate (ASP).
The EAAs bind to NMDA and non-NMDA (AMPA and kainate) receptors
on the postsynaptic neuron, causing calcium and sodium ions to
enter the cell. Increased intracellular calcium leads to rapid
expression of the early response genes, i.e., c-fos. Following
translation in the cytoplasm, FOS protein and other early response
gene products bind to regulatory sites (AP-1) on DNA in the nucleus,
stimulating transcription of the late response genes. The protein
products of the late response genes determine the fate of the
neuron.
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