Neuroactive Steroids Induce Changes in Fetal Sheep Behavior During Normoxic and Asphyxic States

The study investigated the effects of suppressing allopregnanolone production on fetal sheep behavior during normoxic and asphyxic states using finasteride, a 5α-reductase inhibitor. The research involved fetal sheep at approximately 130 days of gestation, with treatments including finasteride, alfaxalone (a synthetic analog of allopregnanolone), and their combination. Finasteride alone increased arousal-like activity and prolonged sub-low voltage ECoG activity after umbilical cord occlusion (UCO), while alfaxalone co-infusion reduced these effects. Alfaxalone treatment also decreased aberrant EEG spikes and restored ECoG activity to normal patterns post-UCO. The findings demonstrated that neurosteroids played a crucial role in modulating CNS activity and mitigating asphyxia's impact on the fetal brain.