Intercellular Conduction Optimizes Arterial Network Function and Conserves Blood Flow Homeostasis During Cerebrovascular Challenges

Autor: Shaun L. Sandow, Cam Ha T. Tran, Anil Zechariah, Bjørn Olav Hald, Michelle Sun Mi Kim, Maria Sancho, Ursula I. Tuor, Donald G. Welsh, Grant R. Gordon, Sergio Fabris
Rok vydání: 2020
Předmět:
Male
Middle Cerebral Artery
Cerebral arteries
Stimulation
Cell Communication
030204 cardiovascular system & hematology
Connexins
Brain Ischemia
Cerebral circulation
0302 clinical medicine
Heart Rate
Homeostasis
Mice
Knockout
0303 health sciences
Chemistry
Models
Cardiovascular
Vascular biology
Gap Junctions
Arteries
Middle Aged
Arterial tree
Stroke
Vasodilation
Vessel diameter
medicine.anatomical_structure
Cerebral blood flow
Cerebrovascular Circulation
Cardiology
Female
Cardiology and Cardiovascular Medicine
Perfusion
Adult
medicine.medical_specialty
Stimulus (physiology)
Article
03 medical and health sciences
Neural activity
Internal medicine
medicine
Animals
Humans
Computer Simulation
030304 developmental biology
business.industry
Electric Conductivity
Endothelial Cells
Blood flow
Neurovascular bundle
Mice
Inbred C57BL
Disease Models
Animal
Vascular resistance
Neurovascular Coupling
business
Neuroscience
030217 neurology & neurosurgery
Zdroj: Arterioscler Thromb Vasc Biol
ISSN: 1524-4636
1079-5642
Popis: Cerebral arterial networks match blood flow delivery with neural activity. Neurovascular response begins with a stimulus and a focal change in vessel diameter, which by themselves is inconsequential to blood flow magnitude, until they spread and alter the contractile status of neighboring arterial segments. We sought to define the mechanisms underlying integrated vascular behavior and considered the role of intercellular electrical signalling in this phenomenon. Electron microscopic and histochemical analysis revealed the structural coupling of cerebrovascular cells and the expression of gap junctional subunits at the cell interfaces, enabling intercellular signaling among vascular cells. Indeed, robust vasomotor conduction was detected in human and mice cerebral arteries after focal vessel stimulation; a response attributed to endothelial gap junctional communication, as its genetic alteration attenuated this behavior. Conducted responses was observed to ascend from the penetrating arterioles, influencing the contractile status of cortical surface vessels, in a simulated model of cerebral arterial network. Ascending responses recognisedin vivoafter whisker stimulation, were significantly attenuated in mice with altered endothelial gap junctional signalling confirming that gap junctional communication drives integrated vessel responses. The diminishment in vascular communication also impaired the critical ability of the cerebral vasculature to maintain blood flow homeostasis and hence tissue viability, after stroke. Our findings establish the integral role of intercellular electrical signalling in transcribing focal stimuli into coordinated changes in cerebrovascular contractile activity and expose, a hitherto unknown mechanism for flow regulation after stroke.SignificanceNeurovascular responses are viewed as a one step process whereby stimuli derived from neural cells focally diffuse to a neighboring vessel, altering its contractile state. While focal changes in tone can subtly tune flow distribution, they can’t substantively change “perfusion magnitude” as vascular resistance is broadly distributed along the cerebral arterial tree. We report that nature overcomes this biophysical constraint by conducting electrical signals among coupled vascular cells, along vessels, and across branch points. Our quantitative exploration of intercellular conduction illustrates how network coordination optimizes blood flow delivery in support of brain function. Diminishing the ability of vascular cells to electrically communicate, mitigates the brain’s ability to regulate perfusion during functional hyperemia and after stroke, the latter advancing tissue injury.
Databáze: OpenAIRE
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