Programming effects of early-life experiences

Sanne Claessens

‘The overall aim of the LifeSpan network is to establish the relationship between early-life events, and late-life survival, and health, and to identify the mechanisms that underpin this relationship’ (

Exposure to early-life adversity is associated with an increased risk for developing psychopathologies in later life, in addition to alterations in stress responsiveness, emotionality and cognitive performance. In this project we investigate the impact of a range of early-life experiences on these parameters throughout different life stages.
This project aims to deepen our understanding of the mechanisms by which early-life experiences 'program' individual differences throughout life. We focus mainly on the role of stress and glucocorticoids in the development of this phenomenon.

For this project we developed 2 different rodent models; one using a naturalistic, mainly behavioral approach and the other using a more invasive, pharmacological approach.

1)    The first model focuses on the impact of naturally occurring variations in maternal care on stress responsiveness of the offspring in later-life. Our results show that very subtle within-litter differences in maternal care result in long lasting differences in stress responsiveness in the offspring.
2)    In the second model we focus on the impact of neonatal dexamethasone treatment; a widely used treatment for respiratory distress syndrome in prematurely born infants that has severe neurodevelopmental side effects. In our search for mechanisms underlying these neurodevelopmental alterations, we show that this treatment acutely affects hippocampal cell proliferation and glial activity in the developing brain.

We plan to extensively describe the health span –in terms of endocrine, immune and metabolic profile- but also the stress responsiveness and cognitive performance of these animals at different life stages and we aim to investigate the link between the acute developmental alterations (‘programming’) and the performance and health span of these animals in later life.