Synaptic activity mediates death of hypoxic neurons.

Cultured hippocampal neurons, when exposed to cyanide or an anoxic atmosphere in the early stages of differentiation, were not visibly affected. However, neurons in the mature cultures died when exposed to cyanide or anoxia. Cell death could be prevented by treatment with magnesium, which eliminates synaptic activity. These observations suggest that damage in hypoxic neurons is mediated by synaptic activity.