Prenatal stress effects on emotion regulation differ by genotype and sex in prepubertal rats

Area of Science:

• Neuroscience
• Behavioral Science
• Developmental Psychology

Background:

• Prenatal stress (PNS) is a significant environmental factor influencing offspring neurodevelopment and behavior.
• Genetic background and sex are known moderators of stress responses and behavioral outcomes.

Purpose of the Study:

• To investigate the behavioral effects of different prenatal stress (PNS) schedules in prepubertal WKY and Wistar rats.
• To examine the interaction between PNS, sex, and genetic background on anxiety- and depressive-like behaviors.

Main Methods:

• Pregnant dams of WKY and Wistar rats were exposed to daily restraint stress, random stress, or no stress during specific gestational periods.
• Offspring were assessed for social play, depressive-like behavior (forced swim test), anxiety-like behavior (open field, novelty tests), and corticosterone levels.

Main Results:

• PNS increased anxiety-like behaviors in WKY rats, particularly females, and reduced depressive-like behavior in the swim test, associated with high corticosterone levels.
• In Wistar rats, PNS led to weight loss, hyperactivity, and increased risk-taking behavior, especially in males.
• Results indicate sex and genetic differences in responses to PNS.

Conclusions:

• The gestational environment significantly influences long-term behavioral outcomes in offspring.
• Interactions between prenatal stress, sex, and genetic factors shape anxiety and depressive-like behaviors.
• HPA axis over-responsiveness may underlie some observed behavioral changes, rather than a true normalization of stress reactivity.