Acute hypoxia exposure following prenatal stress impairs hippocampus and novelty-seeking behavior in adolescent rats

Int J Dev Neurosci. 2022 Feb;82(1):85-95. doi: 10.1002/jdn.10162. Epub 2021 Dec 20.

Abstract

Objectives: The present study aimed to investigate the effects of acute hypoxia exposure following prenatal stress on the novelty-seeking behavior and hippocampus of adolescent rats.

Methods: The offspring were divided into prenatal stress (PS) and non-stress (NS) groups. Both groups were exposed to hypoxia on postnatal day 10 (P10) while control groups were undisturbed. Novel object recognition task was performed in each group. Next, brains were collected to examine hippocampus via immunohistochemical and biochemical studies on postnatal day 35 (P35).

Results: PS decreased novelty discrimination and synaptophysin (SYN) expressions in both CA1 and CA3 of the hypoxia group prominently (p < 0.05). Nestin-expressing cells were reduced while vascular endothelial growth factor (VEGF) expression was enhanced in the subgranular zone (SGZ) of PS-hypoxia group (p < 0.05). VEGF enhancement triggered angiogenesis in the CA1 and CA3 significantly (p < 0.05). PS also increased thiobarbituric acid reactive substances (TBARS) levels in the hypoxia group as a result of oxidative stress (p < 0.05).

Conclusion: These findings demonstrated that PS exacerbates neurodevelopmental deficits in the hippocampus of acute hypoxia-induced offspring in adolescence.

Keywords: hippocampus; hypoxia; novelty-seeking; prenatal stress.

MeSH terms

  • Animals
  • Exploratory Behavior*
  • Female
  • Hippocampus / metabolism
  • Hypoxia / metabolism
  • Pregnancy
  • Prenatal Exposure Delayed Effects* / metabolism
  • Rats
  • Stress, Psychological
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Vascular Endothelial Growth Factor A