Hippocampal Dendritic Spines Modifications Induced by Perinatal Asphyxia

Abstract

Perinatal asphyxia (PA) affects the synaptic function and morphological organization. In previous works we have shown neuronal and synaptic changes in rat neostriatum subjected to hypoxia leading to long term ubi-protein accumulation. Since F-actin is highly concentrated in dendritic spines, modifications in this proteins their organization could be related with alterations induced by hypoxia in the Central Nervous System. In the present study, we investigate the effects of PA on the actin cytoskeleton of hippocampal post-synaptic densities (PSD) in 4-month-old rats. PSD showed an increment in their thickness and in the level of ubiquitination. Correlative fluorescence-electron microscopy photooxidation showed a decrease in the number of F-actin stained spines in hippocampal excitatory synapses subjected to PA. Although Western blot analysis also showed a sligth decreased in beta-actin in PSD in PA animals the difference was not significant. Take together, this data suggests that long term actin cytoskeleton might have role in PSD alterations which would be a spread phenomena induced by PA.