Medical Research Council - London Institute of Medical Sciences

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Two-photon excitation fluorescence microscopy brings new level of detail to imaging tiny blood vessels

21 March 2021

Brain Capillaries Captured

Clinical imaging can provide a view of blood flow through the veins and arteries of the brain, but such techniques fall short when it comes to viewing the far smaller capillaries. To study these tiny vessels in action, scientists have turned to animal models and to a specialised form of fluorescence microscopy, called two-photon imaging, which allows observations of living tissues at greater thicknesses than traditionally possible. The researchers engineered mice to enable visualisation and manipulation of the animals’ pericytes – the cells surrounding capillaries. And, the result is an extraordinary view of capillary structure and flow, as seen in this video (pericytes, red; capillary flow, green). The team also gained insights into pericyte function, showing these cells can control capillary constriction. Such detailed views of the brain’s tiniest vessels will likely have implications for all sorts of neurological conditions where blood flow is impaired, such as neurodegeneration and stroke.

Written by Ruth Williams

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