TRANSNEURONAL DEGENERATION IN BRAINS OF MONKEYS ASPHYXIATED AT BIRTH

Brain damage occurring from 10 months to 8 years 9 months after neonatal asphyxiation for 11.5-17 min was assessed histologically in 12 rhesus monkeys. Comparison was made with brains of ten monkeys asphyxiated for brief periods or living shorter times and with those of five nonasphyxiated controls. Very slight damage occurred after 6-7 min of asphyxia; major destruction of relay nuclei in afferent input systems and parts of the basal ganglia, after 11.5-17 min. In the course of time, beginning about 10 months after birth, secondary transneuronal degeneration became evident. This was most clearly seen in the parts of the cerebral cortex which had received projections from the thalamic nuclei destroyed during the asphyxia; also in other thalamic nuclei and the brain-stem reticular formation. Gradual improvement in physical status and in behavioral responses to environment occurred while brain structure deteriorated. © 1969.