Ultraflexible endovascular probes for brain recording through micrometer-scale vasculature

Science, Journal Year: 2023, Volume and Issue: 381(6655), P. 306 - 312

Published: July 20, 2023

Implantable neuroelectronic interfaces have enabled advances in both fundamental research and treatment of neurological diseases but traditional intracranial depth electrodes require invasive surgery to place can disrupt neural networks during implantation. We developed an ultrasmall flexible endovascular probe that be implanted into sub-100-micrometer-scale blood vessels the brains rodents without damaging brain or vasculature. In vivo electrophysiology recording local field potentials single-unit spikes been selectively achieved cortex olfactory bulb. Histology analysis tissue interface showed minimal immune response long-term stability. This platform technology readily extended as tools medical devices for detection intervention diseases.

Language: Английский

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Pericytes and the Control of Blood Flow in Brain and Heart

Annual Review of Physiology, Journal Year: 2023, Volume and Issue: 85(1), P. 137 - 164

Published: Feb. 10, 2023

Pericytes, attached to the surface of capillaries, play an important role in regulating local blood flow. Using optogenetic tools and genetically encoded reporters conjunction with confocal multiphoton imaging techniques, 3D structure, anatomical organization, physiology pericytes have recently been subject detailed examination. This work has revealed novel functions morphological features such as tunneling nanotubes brain microtubes heart. Here, we discuss state our current understanding roles flow control heart, where may differ due distinct spatiotemporal metabolic requirements these tissues. We also outline concept electro-metabolic signaling, a universal mechanistic framework that links tissue regulation by vascular smooth muscle cells, capillary K ATP Kir2.1 channels primary sensors. Finally, present major unresolved questions how they can be addressed.

Language: Английский

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Stimulation-induced increases in cerebral blood flow and local capillary vasoconstriction depend on conducted vascular responses

Proceedings of the National Academy of Sciences, Journal Year: 2018, Volume and Issue: 115(25)

Published: June 4, 2018

Significance Pericytes are located at the outside wall of capillaries. However, whether and how pericytes involved in regulation blood flow brain capillaries is still debated. We report that capillary vascular responses mostly initiated peak near-arteriole These conducted along a speed 5–20 µm/s. Conducted appear to involve pericytes, mural cells microvessels, may be novel modulator function brain.

Language: Английский

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Benchmarking in vitro tissue-engineered blood–brain barrier models

Fluids and Barriers of the CNS, Journal Year: 2018, Volume and Issue: 15(1)

Published: Dec. 1, 2018

The blood-brain barrier (BBB) plays a key role in regulating transport into and out of the brain. With increasing interest BBB health disease, there have been significant advances development vitro models. value these models to research community is critically dependent on recapitulating characteristics humans or animal However, benchmarking surprisingly difficult since much our knowledge structure function comes from studies. Here we describe set parameters that consider starting point for validation. These are associated with (ultrastructure, wall shear stress, geometry), microenvironment (basement membrane extracellular matrix), (transendothelial electrical resistance, permeability, efflux transport), cell (expression markers, turnover), co-culture other types (astrocytes pericytes). In suggesting benchmarks, rely primarily imaging direct measurements

Language: Английский

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Mechanisms Mediating Functional Hyperemia in the Brain

The Neuroscientist, Journal Year: 2017, Volume and Issue: 24(1), P. 73 - 83

Published: April 12, 2017

Neuronal activity within the brain evokes local increases in blood flow, a response termed functional hyperemia. This ensures that active neurons receive sufficient oxygen and nutrients to maintain tissue function health. In this review, we discuss functions of hyperemia, types vessels generate response, signaling mechanisms mediate neurovascular coupling, communication between vessels. Neurovascular coupling is mediated primarily by vasoactive metabolites arachidonic acid (AA), nitric oxide, K+. While much known about these pathways, many contentious issues remain. We highlight two controversies, role glial cell Ca2+ mediating importance capillaries generating propose pathways resolve controversies. scheme, capillary dilations are generated astrocyte endfeet, leading production AA metabolites. contrast, arteriole neurons, resulting oxide Arachidonic from also diffuses into endfeet where it converted additional scheme resolves several discrepancies field, unresolved challenges remain discussed final section review.

Language: Английский

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Depth-dependent flow and pressure characteristics in cortical microvascular networks

PLoS Computational Biology, Journal Year: 2017, Volume and Issue: 13(2), P. e1005392 - e1005392

Published: Feb. 14, 2017

A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding neurovascular coupling mechanisms related measurement techniques. Here, numerical simulations with discrete tracking red blood cells (RBCs) are performed three from mouse cerebral cortex. Our analysis based on trajectories individual RBCs focuses layer-specific phenomena until a cortical depth 1 mm. The RBC reveal that capillary bed preferentially move plane. Hence, field shows laminar patterns valid. We demonstrate entering close to surface (< 400 μm) largest drop takes place capillaries (37%), while deeper regions arterioles responsible 61% total drop. Further characteristics, such as transit time or velocity, also vary significantly over depth. Comparison purely topological characteristics flow-based ones combined interpretation topology indispensable. results provide evidence it crucial consider differences all investigations vasculature. These findings support hypothesis an efficient oxygen up-regulation at least two regulation must be playing hand hand, namely increase homogenization. However, contribution both likely varies

Language: Английский

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Vascular and neural basis of the BOLD signal

Current Opinion in Neurobiology, Journal Year: 2019, Volume and Issue: 58, P. 61 - 69

Published: July 20, 2019

Language: Английский

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Multiscale modelling of blood flow in cerebral microcirculation: Details at capillary scale control accuracy at the level of the cortex

PLoS ONE, Journal Year: 2018, Volume and Issue: 13(1), P. e0189474 - e0189474

Published: Jan. 11, 2018

Aging or cerebral diseases may induce architectural modifications in human brain microvascular networks, such as capillary rarefaction. Such limit blood and oxygen supply to the cortex, possibly resulting energy failure neuronal death. Modelling is key understanding how these affect flow mass transfers complex networks. However, huge number of vessels brain-tens billions-prevents any modelling approach with an explicit representation down scale capillaries. Here, we introduce a hybrid model at larger microcirculation, based on its multiscale architecture. The bed, which space-filling network, treated porous medium modelled using homogenized continuum approach. arteriolar venular trees, cannot be because their fractal-like nature, are network interconnected tubes detailed spatial organization. main contribution this work devise proper coupling interface between two components. This analytical approximations pressure field that capture strong gradients building up capillaries connected arterioles venules. We evaluate accuracy for both very simple architectures one arteriole and/or venule more ones, anatomically realistic tree-like displaying large sites. show accurate describing scales further yields significant computational gain by comparison classical It therefore important step towards simulations lays groundwork introducing additional levels complexity future.

Language: Английский

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Brain microvasculature has a common topology with local differences in geometry that match metabolic load

Neuron, Journal Year: 2021, Volume and Issue: 109(7), P. 1168 - 1187.e13

Published: March 2, 2021

Language: Английский

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Pericyte Structural Remodeling in Cerebrovascular Health and Homeostasis

Frontiers in Aging Neuroscience, Journal Year: 2018, Volume and Issue: 10

Published: July 17, 2018

The biology of brain microvascular pericytes is an active area research and discovery, as their interaction with the endothelium critical for multiple aspects cerebrovascular function. There growing evidence that pericyte loss or dysfunction involved in pathogenesis Alzheimer's disease, vascular dementia, ischemic stroke injury. However, strategies to mitigate compensate this remain limited. In review, we highlight a novel finding adult are structurally dynamic vivo, actively endothelial coverage by extending far-reaching processes maintain contact regions exposed endothelium. Structural remodeling may present opportunity foster pericyte-endothelial communication should be explored potential means counteract dementia disease. We discuss pathophysiological consequences on capillary function, biochemical pathways control remodeling. also offer guidance observing such structural can more broadly studied mouse models

Language: Английский

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