Programming effects of lactational stress

Contact: Prof. Dr. Ulrike Gimsa

Duration: 2021-2024

Funding: Deutsche Forschungsgemeinschaft, DFG GI 413/4-1 / AOBJ: 674330

Research in humans as well as other animal species has demonstrated critical developmental periods for offspring during which exposure to acute or chronic adverse events, either directly or indirectly via impacts to mothers, can trigger permanent changes to the offspring’s neurocognitive, physiological and immune systems. The goals of this project are to investigate the various mechanisms by which stress to mothers during the lactational period exerts so-called ‘programming effects’ on offspring, using a novel pig model. As the basis for our research, sows and their offspring will be independently exposed to low or high levels of stress during the lactational period. We will induce high stress conditions via administration of the HPA-axis stimulating adrenocorticotropic hormone (ACTH). We will then investigate various pathways by which programming effects may be transmitted to offspring, via alterations in milk composition or maternal care. Offspring from different early maternal environments will also undergo an acute maternal separation either alone (high stress condition) or with litter mates present for social support (low stress condition). This will allow us to evaluate the impacts of both indirect and direct stressors on offspring development. In addition to collecting behavioral data on mother-offspring social interactions, we will also measure cortisol as an indicator of stress, oxytocin as an indicator of social support and alterations in immune cell composition and function in response to immune challenges. We will measure long-term impacts of early maternal environment on environmental and social challenges later in life, including weaning and mixing in new social groups and exposure to novelty. We will also investigate gene-expression of stress-related genes and oxytocin and its receptors to determine long-term programming effects on brain development. In addition to the translational implications in identifying potential mediators of programming effects in humans, our research will also have applied value by identifying interventions that may reduce piglet mortality and improve welfare of pigs in livestock farming.