Postnatal administration of L-dopa normalizes hypoxia-induced long-term changes in dopamine release from striatum slices and in avoidance learning.

Newborn rats exposed to a mild chronic postnatal hypoxia always displayed at the age of 2-3 months an increased fractional efflux rate of dopamine (DA) from striatum slices combined with a decreased capacity for learning and retention. The protective effect of the administration of L-DOPA on these long-term changes was tested by the injection of L-DOPA 5-30 min prior to the beginning of daily exposure to hypoxia. L-DOPA administration during postnatal hypoxia prevents in a dose dependent manner the long-term effects of postnatal hypoxia as described. This finding supports the hypothesis that long-term changes in DA release and in behaviour due to early postnatal hypoxia may be brought about by changes in the DA-metabolism during a critical period of development.