Finetuning the Immune System to be More Resilient to Stress

Stress is a systemic physiological and behavioral response to what an organism perceives as threat. Resilience to the same stressful event varies within a population. However, it remains challenging to identify resilience in mammalian embryos to determine if stress resilience is established as a trait during development or acquired later in life.

Aim:
To understand whether vertebrates display differential stress response early in life, and to study the factors contributing to the establishment of stress resilience/susceptibility during development.

Methods:
Zebrafish exhibit stress responsive behavior early in life. We developed novel behavioural strategies to measure stress resilience in larval and adult zebrafish. To study the molecular mechanisms underlying stress resilience, we employed transcriptomic analysis.

Results:
We show that resilience is a trait in genetically identical populations that is determined at early stages of development. Stress resilience is maintained as the fish grow to become adults and is passed on to the next generation. At the molecular level, resilience is positively regulated by neuropeptides and negatively regulated by the innate immune complement pathway.

Conclusions:
Resilience is established early during development as a stable trait and is regulated by neuropeptides and the immune system.