Maiken Nedergaard

Danish-American neuroscientist. Frank P. Smith Professor of Neurosurgery at the University of Rochester Medical Center, where she co-directs the Center for Translational Neuromedicine; in parallel, since 2014, she directs the Center for Translational Neuromedicine at the University of Copenhagen. MD/DMSc from the University of Copenhagen (1988). The principal architect of the glymphatic-system framework for brain interstitial-fluid clearance.

Stake§

Nedergaard's stake is scientific, clinical, and substantial. The glymphatic programme has been funded heavily by NIH, the Lundbeck Foundation, and the Novo Nordisk Foundation; the framework's implications for ageing, sleep medicine, and neurodegeneration have drawn substantial pharmaceutical interest. The two-institution arrangement (Rochester and Copenhagen) is unusual at this level and reflects both her scientific standing and the international funding base of the programme.

The 2012 Science Translational Medicine paper with Jeffrey Iliff and the 2013 Science paper with Lulu Xie are the two papers that established the glymphatic system as a recognised feature of brain physiology. The framework — astrocyte-mediated CSF-interstitial bulk-flow clearance of metabolic waste, driven by arterial pulsation and sleep-regulated — extended the older interstitial-fluid physiology into a specifically neuroscientific domain that had long been thought to lack lymphatic clearance.

The post-2012 programme has extended in several directions: sleep-driven clearance and its implications for ageing (Xie 2013), glymphatic dysfunction in Alzheimer's, the role of aquaporin-4 in astrocyte mediation, and the connection between meningeal lymphatic vessels and the glymphatic system that Louveau and Kipnis 2015 established from the lymphatic side. The strong version of the bulk-flow model has been contested (Smith and Verkman 2018; Hladky and Barrand reviews) and the field continues to work out the precise mechanism.

Nedergaard is the figure who turned brain interstitial-fluid clearance from a marginal physiology question into a central neurobiology framework. The criticisms — that the bulk-flow model overstates convection over diffusion, that the public-facing sleep cleans the brain framing has outrun the empirical case — are familiar from popular-science- adjacent neuroscience. The journal work is careful; the popularisation has sometimes been less so.