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Rapid and local autoregulation of cerebrovascular blood flow: a deep‐brain imaging study in the mouse
Author(s) -
Kuga Nahoko,
Hirata Tadashi,
Sakai Ikuko,
Tanikawa Yoshihisa,
Chiou Huei Yu,
Kitanishi Takuma,
Matsuki Norio,
Ikegaya Yuji
Publication year - 2009
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2008.163253
Subject(s) - autoregulation , cerebral autoregulation , hippocampal formation , cerebral blood flow , blood flow , baroreflex , blood pressure , neuroscience , homeostasis , medicine , hemodynamics , cardiology , anesthesia , biology , heart rate
The brain obtains energy by keeping the cerebral blood flow constant against unexpected changes in systemic blood pressure. Although this homeostatic mechanism is widely known as cerebrovascular autoregulation, it is not understood how widely and how robustly it works in the brain. Using a needle‐like objective lens designed for deep‐tissue imaging, we quantified the degree of autoregulation in the mouse hippocampus with single‐capillary resolution. On average, hippocampal blood flow exhibited autoregulation over a comparatively broad range of arterial blood pressure and did not significantly respond to pressure changes induced by the pharmacological activation of autonomic nervous system receptors, whereas peripheral tissues showed linear blood flow changes. At the level of individual capillaries, however, about 40% of hippocampal capillaries did not undergo rapid autoregulation. This heterogeneity suggests the presence of a local baroreflex system to implement cerebral autoregulation.