Behavioral performance of rats following neonatal hypoxia-ischemia.

The behavioral performance of rats subjected in the neonatal period to hypoxia-ischemia at either 37 degrees C or 21 degrees C was compared to that of sham-ligated animals. Performance on complex motor tests was significantly delayed only in the hypoxic-ischemic 37 degrees C rats. However, cognitive testing disclosed significant delay of spatial learning in animals subjected to hypoxia-ischemia at 21 degrees C and those with gross infarction at 37 degrees C. There was enhanced avoidance learning in the animals with gross infarction in the hypoxia-ischemia 37 degrees C group. Hypoxic-ischemic damage in the neonatal rat at 37 degrees C results in transient delay of complex motor skills, but longer lasting cognitive changes. Hypoxia-ischemia during hypothermia produces no motor deficits, although there may be similar alterations in learning.