Hypoxic-ischemic damage in the neonatal brain: excitatory amino acids.

Perinatal brain damage is a major clinical problem. Recent studies suggest that excitatory amino acids (EAAs) may be important for the development of hypoxic-ischemic brain injury in the newborn. Experimental work demonstrates that the immature brain is hypersensitive to the toxic effects EAA ('excitotoxicity'), hypoxic-ischemia is accompanied by an extracellular overflow of EAAs and hypoxic-ischemic brain damage is reduced by EAA receptor antagonists. Clinical investigations demonstrate the presence of EAA receptors in vulnerable areas of the newborn human brain and the concentrations of EAAs in the cerebrospinal fluid are higher in asphyxiated than in control infants. Clinical studies are warranted to evaluate the importance of excitotoxicity for development of brain lesions after severe asphyxia.