We are recruiting a PhD candidate to investigate how the brain’s microvascular network adapts to repeated, severe hypoxia—an issue central to understanding vascular contributions to neurodegeneration and dementia in humans.

Scientific context and hypothesis: The mammalian brain has the highest basal energy demand and is highly vulnerable to both acute and chronic oxygen deprivation, which can trigger neuronal death or vascular cognitive decline. Recent work suggests that intrinsic heterogeneity in cerebral microvascular flow creates low-oxygen microregions, limiting resilience to additional stressors such as capillary loss or hypoperfusion. We hypothesize that, under repeated hypoxic stress, the cerebrovascular system activates compensatory remodeling that reduces this heterogeneity and preserves neuronal oxygenation.

Objectives:

- Quantify age- and region-dependent changes in microvascular architecture (cortex, cerebellum, hypothalamus, hippocampus) in southern elephant seals (Mirounga leonina) versus common seals (Phoca vitulina), correlating structural variability with lifetime hypoxia exposure.

- Use multiscale modeling of microvascular blood flow and oxygen transport to test whether developmental vascular remodeling in elephant seals reduces flow/transport heterogeneity more strongly than in common seals, and to explore limits of adaptation linked to premature aging.

Methods:

The project combines comparative neuroanatomy and biophysical modeling. Brains from juvenile and adult elephant seals (already collected) and common seals will be tissue-cleared, immunolabeled, and imaged by light-sheet microscopy to reconstruct 3D microvascular networks. Architectural descriptors will feed into IMFT’s established multiscale simulations of coupled flow–oxygen transport in brain tissue.

Training and environment:

The 3-year PhD is co-supervised by J. Badaut, Centre d’Études Biologiques de Chizé (CEBC; marine mammal ecophysiology) and Sylvie Lorthois, Toulouse Institute of Fluid Mechanics (IMFT; cerebral microcirculation modeling). The candidate will spend 18 months at each site, gaining expertise in advanced imaging, quantitative vascular analysis, and computational physiology, with direct relevance to human cerebrovascular health.