Preserved striatal tyrosine hydroxylase activity, assessed in vivo, following neonatal hypoxia-ischemia.

Previous in vitro studies have shown that biochemical indices of striatal dopaminergic systems are preserved following neonatal hypoxia-ischemia. There has been no previous assessment of these systems in vivo. Using the accumulation of striatal dopa following administration of a dopa decarboxylase inhibitor as an in vivo measure of tyrosine hydroxylase (TH) activity, we have found that baseline TH activity, and its regulation by both neuronal activity and presynaptic autoreceptors are also preserved following hypoxia-ischemia.