[Involvement of excitatory amino acids in the brain damage of neonatal asphyxia]

Besides their role as neurotransmitters, excitatory amino acids (EAAs) in the developing brain are crucially involved in plasticity and excitotoxicity which are modified by their distinct ontogeny. Postsynaptic EAA system activities, particularly of the N-methyl-D-aspartate and quisqualate receptors, are transiently enhanced early in life. This transient enhancement is presumably beneficial to the immature brain because physiologic activation of the EAA system plays a critical role in plasticity of early learning and morphogenesis. At the same time, this transient hypersensitivity renders the immature brain vulnerable to pathologic excitation of the EAA system (excitotoxicity) as observed during neonatal hypoxia-ischemia.