Adulthood behavioral and neurodevelopmental effects of being raised by an ambivalent mother in rats: What does not kill you makes you stronger

Abstract

Background/aim: This study aimed to investigate the effects of early adverse life events and being raised by an ambivalent mother on rats. Materials and methods: The rats were separated into four groups: 1) the control group (n = 12), which was raised under standard care; 2) the early handling (EH) group, which was raised using an EH model (n = 16); 3) the early deprivation (ED) group, which was raised using an ED model (n = 13), and 4) the ambivalent mother (AM) group, which spent 3 h/day with a “fake mother” (n = 17). When they became adults, their anxiety levels, depressive-like behaviors, and memory functions were measured using the elevated plus maze test, the forced swim test, and the novel object recognition test, respectively. Their neurodevelopment was evaluated by measuring the brain-derived neurotrophic factor (BDNF) levels in the prefrontal cortex, the dentate gyrus, and the cerebellum via ELISA. Results: The rats in the ED and AM groups exhibited less anxiety and depressive-like behavior than those in the control and EH groups, particularly in females. There was no significant difference between the groups in memory function or brain BDNF levels. Conclusion: Severe and ambivalent early adverse life events may decrease anxiety and depressive-like behavior in adult rats.