New insights into mechanisms of neuronal damage in the developing brain.

Hypoxia-ischemia, hypoglycemia, and status epilepticus damage specific regions in the developing brain. The factors which determine selective neuronal vulnerability have remained obscure but recent research suggests that the patterns may be related to dysfunction of specific sets of synapses. An important current hypothesis suggests that hyperactivity of excitatory synapses, which use neurotransmitters such as glutamate, may cause excessive transmitter release and lead to damage of adjacent neurons. Excessive stimulation of excitatory neurotransmitter receptors triggers a cascade of biochemical reactions and potentially lethal ionic shifts. Recent observations suggest that drugs acting at these receptors could be used to reduce brain injury caused by a variety of insults to the developing brain.