Abstracts are provided in the language submitted.

Introduction: Adolescence is a period of transition during which there is extensive development of the brain and the hypothalamic-pituitary-adrenal axis. This makes this a period which is particularly susceptible to the long-term behavioural impacts of chronic stress. Methods: Using a predator stress model, we investigated the effects of chronic psychological stress on anxiety-like, depression-like, and social behaviours in male and female mice. Stress treatments were performed during early adolescence, when mice were pre-pubertal, or late adolescence, when mice were sexually mature. Results: All stressed mice showed hyperactivity, increased anxiety-like behaviours, and increased pro-social behaviours. In general, effects of adolescent stress were most pronounced in mice exposed during late, rather than early adolescence, although this was not the case for all measures. Mice exposed to stress during early adolescence also provided less maternal care towards their first litter of pups, and their offspring, in turn, presented increased anxiety-like and depressive-like behaviours. Conclusion and Significance: This suggests that adolescent stress results in intergenerational effects on behaviour via a social mechanism of transmission.

Dr. Tamara Franklin