Cerebellar abnormalities following hypoxia alone compared to hypoxic–ischemic forebrain injury in the developing rat brain

Two-day-old (P2) rat pups were subjected to either a global hypoxia or to electrocoagulation of the right carotid artery followed by 2.5 h hypoxia. Cellular and regional injury in the cerebellum (CB) was studied at 1, 2 and 19 days using immunohistology. Following hypoxia and hypoxia–ischemia, all neuronal populations of the CB were damaged in a subset of Purkinje cells. The decrease in the number of interneurons, as well as the thickness of molecular and granular layers was significant following hypoxia. Diffuse white matter damage, with loss of preoligodendrocytes was more severe following hypoxia than hypoxia–ischemia. Global hypoxia in the rat at P2 produces extensive damage to many cell types in different areas of the CB. The addition of unilateral forebrain ischemia does not increase the severity of these changes. Our data provide insight into the mechanisms of the changes observed in the CB of premature newborns.

Research Highlights
► Hypoxia alone in the rat at P2 produces cerebellar damage.
► Following hypoxia and hypoxia–ischemia, all neuronal populations of the cerebellum were damaged.
► Diffuse white matter damage was more severe following hypoxia than hypoxia–ischemia.
► These data may explain some neurodevelopmental abnormalities in preterm infants.