Poster Presentation ANZOS Annual Scientific Meeting 2021

An investigation of combined effects of maternal obesity and hypoxic-ischemic (HI) brain injury on rat offspring (#201)

Bharti Biswas 1 , Valsamma Eapen 1 , Nicole Jones 1 , Margaret Morris 1
  1. University of new south wales Sydney, Kingsford, NSW, Australia

Maternal obesity is associated with pregnancy-related complications including birth asphyxia. As both maternal obesity and neonatal HI injury have detrimental effects on neurodevelopmental outcomes, here we examined their combined effects in adult offspring.

After 7 weeks of chow or High Fat Diet (HFD) (n=10, 8) female Sprague Dawley rats were mated with chow-fed males. On postnatal day 7, the right common carotid artery of pups was occluded followed by hypoxia (7.5% O2, 3 hours) (HI); controls underwent sham surgery. Behavioural outcomes including anxiety and social interaction were studied between 6-14 weeks of age.

Before mating, HFD mothers were ~11.1% heavier (p<0.05) than Chow. From week 4-13, male HFD were heavier than chow offspring (p<0.05); Chow HI were lighter than Chow sham and maternal HFD HI offspring (diet×HI interaction, p<0.05) suggesting maternal HFD mitigated the effect of HI. No effect of HFD or HI on body weight was observed in female offspring. In a social interaction 3-chamber test, male HI spent significantly less time interacting with the novel rat than Sham offspring (p<0.05) and offspring from HFD mothers showed higher % preference for novel rat than Chow offspring. No effect of HFD or HI was observed on social interaction in females. In the elevated plus maze, female offspring of HFD mothers spent more time in the open arm (p<0.05) indicating reduced anxiety. Conversely, in the open field test a significant HI effect was observed in male, but not female offspring; HI males spent more time in centre than sham indicating reduced anxiety.

These data suggest sex-dependent effects of maternal HFD and HI in offspring. In male offspring maternal HFD increased body weight and mitigated the effect of HI after weaning. HI reduced social interaction and anxiety in males and maternal HFD reduced anxiety in females.