In vivo imaging of cerebral microvascular plasticity from birth to death.

Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Journal of cerebral blood flow and metabolism: official journal of the International Society of Cerebral Blood Flow and Metabolism (Impact Factor: 5.46). 10/2012; DOI: 10.1038/jcbfm.2012.152
Source: PubMed

ABSTRACT Cerebral function and viability are critically dependent on efficient delivery of oxygen and glucose through the microvasculature. Here, we studied individual microvessels in the intact brain using high-resolution confocal imaging and long-term time-lapse two-photon microscopy across the lifetime of a mouse. In the first postnatal month, we found large-scale sprouting but to our surprise the majority of sprouts underwent pruning and only a small fraction became perfused capillaries. After the first month, microvessel formation and elimination decreased and the net number of vessels stabilized. Although vascular stability was the hallmark of the adult brain, some vessel formation and elimination continued throughout life. In young adult mice, vessel formation was markedly increased after exposure to hypoxia; however, upon return to normoxia, no vessel elimination was observed, suggesting that new vessels constitute a long-term adaptive response to metabolic challenges. This plasticity was markedly reduced in older adults and aging where hypoxia-induced angiogenesis was absent. Our study describes, for the first time in vivo patterns of cerebral microvascular remodeling throughout life. Disruption of the observed balance between baseline turnover and vascular stability may underlie a variety of developmental and age-related degenerative neurological disorders.Journal of Cerebral Blood Flow & Metabolism advance online publication, 24 October 2012; doi:10.1038/jcbfm.2012.152.

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