Neuro–vascular interactions

  • Article
    | Open Access

    The first known portal system in the mammalian brain was identified in 1933. Here the authors describe a new portal system between the capillary beds of the Suprachiasmatic Nucleus master clock and a circumventricular organ, enabling humoral signals to reach targets without dilution in the systemic circulation.

    • Yifan Yao
    • , Alana B’nai Taub
    •  & Rae Silver
  • Article
    | Open Access

    Theta and gamma rhythms are essential to ensure timely communication between brain structures during locomotion. Here the authors investigate the association between cerebral blood flow and neural oscillations in freely behaving mice running a linear track.

    • Antoine Bergel
    • , Elodie Tiran
    •  & Ivan Cohen
  • Article
    | Open Access

    Monitoring hemodynamics in the brain is important in understanding medical imaging data and mechanisms of disease. Here the authors use high-throughput two-photon microscopy with an axially-extended Bessel focus to measure vessel size and blood flow down to capillary scale in the awake mouse brain.

    • Jiang Lan Fan
    • , Jose A. Rivera
    •  & Na Ji
  • Article
    | Open Access

    Traumatic brain injury (TBI) is a serious and poorly understood medical condition. Here, the authors show that TBI induces long-lasting deficits in brain lymphatic drainage. They report that defects in this drainage pathway provoke severe TBI pathogenesis that can be rescued with VEGF-C treatment.

    • Ashley C. Bolte
    • , Arun B. Dutta
    •  & John R. Lukens
  • Article
    | Open Access

    Precapillary sphincters are mural cells encircling an indentation of blood vessels where capillaries branch off from penetrating arterioles (PAs), but their existence and role in the brain is not fully understood. Here authors describe these structures at PAs in the cortex and show that they constrict during cortical spreading depolarization in mice.

    • Søren Grubb
    • , Changsi Cai
    •  & Martin Lauritzen
  • Article
    | Open Access

    The brain receives 20% of cardiac output, but in accord with the current knowledge lacks a specialized sensor of its own blood flow. Here, the authors show that brain astrocytes detect drops in perfusion and trigger compensatory increases in arterial pressure and heart rate to preserve brain blood flow and oxygen delivery.

    • Nephtali Marina
    • , Isabel N. Christie
    •  & Alexander V. Gourine
  • Article
    | Open Access

    Understanding mechanisms of cerebral oxygen regulation is critical for healthy brain function. Here the authors show that respiration is a key modulator of cerebral oxygenation, which will be helpful in better resolving neurally-generated functional brain imaging signals, such as BOLD fMRI.

    • Qingguang Zhang
    • , Morgane Roche
    •  & Patrick J. Drew
  • Article
    | Open Access

    Detailed characterization of large-scale hemodynamic responses linked to specific neural activity remains to be elucidated at the single-vessel level across the subcentimeter scale hippocampal vasculature in vivo. Here, authors use a novel multi-modal fMRI platform to characterize distinct spatiotemporal patterns of hippocampal hemodynamic responses that were correlated to the optogenetically evoked Ca2+ events and to further demonstrate the significantly reduced neurovascular coupling efficiency upon spreading depression-like Ca2+ events.

    • Xuming Chen
    • , Filip Sobczak
    •  & Xin Yu
  • Article
    | Open Access

    Fiber optic implantation in deep areas of the rodent’s brain for MRI combined with optogenetics is challenging. Here the authors use an MRI-guided robotic arm as the navigation method for accurate fiber optic placement and precise microinjection during multi-modal fMRI, optogenetics and calcium recordings.

    • Yi Chen
    • , Patricia Pais-Roldan
    •  & Xin Yu
  • Article
    | Open Access

    Neuronal activity leads to a local increase in blood flow and volume, a process termed hyperaemia. Here, the authors employ multiple imaging approaches of neuronal and vascular activity at varying resolution to delineate the spatiotemporal dynamics of neurovascular coupling evoked by odours in the olfactory bulb.

    • Davide Boido
    • , Ravi L. Rungta
    •  & Serge Charpak
  • Article
    | Open Access

    The brain primarily uses glucose to generate energy, but the relationship of neuronal activity to glucose utilization is not necessarily a simple linear one. Here, the authors introduce relative power (rPWR) and relative cost (rCST) as new metrics to quantify how brain activity relates to glucose consumption.

    • Ehsan Shokri-Kojori
    • , Dardo Tomasi
    •  & Nora D. Volkow
  • Article
    | Open Access

    Measuring multiple neurophysiologic variables usually requires bulky benchtop optical systems and working with anesthetized animals. Here the authors present a miniature portable microscope for neurovascular imaging in awake rodents, combining fluorescence, intrinsic optical signals and laser speckle contrast.

    • Janaka Senarathna
    • , Hang Yu
    •  & Arvind P. Pathak
  • Article
    | Open Access

    Arterial pulsations are thought to drive CSF flow through perivascular spaces (PVSs), but this has never been quantitatively shown. Using particle tracking to quantify CSF flow velocities in PVSs of live mice, the authors show that flow speeds match the instantaneous speeds of the pulsing artery walls that form the inner boundaries of the PVSs.

    • Humberto Mestre
    • , Jeffrey Tithof
    •  & Douglas H. Kelley
  • Article
    | Open Access

    ApoE4 is a risk factor for small vessel disease, which can lead to cognitive impairment. Here the authors assess the microvasculature of the corpus callosum using 3-photon microscopy and find that mice expressing the ApoE4 allele are more susceptible than wild-type to white matter injury and cognitive impairment in a model of hypoperfusion-induced hypoxia.

    • Kenzo Koizumi
    • , Yorito Hattori
    •  & Costantino Iadecola
  • Article
    | Open Access

    The vascular stem cell niche regulates the proliferation and differentiation of neural stem cells (NSCs) in the adult subventricular zone. Here the authors identify EGFL7 as a neurovascular regulator of NSCsin vivo; EGFL7-knockout mice show reduced neurogenesis, and exhibit impaired olfactory perception and behaviour.

    • Frank Bicker
    • , Verica Vasic
    •  & Mirko H. H. Schmidt
  • Article
    | Open Access

    Physical exercise promotes brain angiogenesis through an unknown signalling cascade. Morlandet al. identify the elusive muscle-brain communication and show that lactate produced by muscle activity binds to its receptor HCAR1 in brain vessel-surrounding cells, stimulating VEGF production and brain angiogenesis.

    • Cecilie Morland
    • , Krister A. Andersson
    •  & Linda H. Bergersen
  • Article
    | Open Access

    Combination of optogenetics and BOLD fMRI is routinely used to map neuronal activity upon photostimulation. Here the authors show that light, shone at intensities used in optogenetic studies, dilates vessels and increases blood flow independently of exogenous light-sensitive proteins in the mouse brain.

    • Ravi L Rungta
    • , Bruno-Félix Osmanski
    •  & Serge Charpak
  • Article
    | Open Access

    Cerebrovascular accumulation of Aβ is a common feature of Alzheimer’s disease, though it is unclear whether mutant vascular amyloid is capable of Aβ seeding. Here, the authors show microvascular amyloid seeds are capable of driving wild-type Aβ to assemble into distinctive anti-parallel fibrillary structures.

    • Feng Xu
    • , Ziao Fu
    •  & William E. Van Nostrand
  • Article
    | Open Access

    Immune system participates in the development of high blood pressure. Here the authors show that cholinergic-sympathetic pathway mediated by the α7nAChR receptor and the activation of splenic T cells prime immunity during hypertension and that selective splenic denervation protects against the onset of hypertension in mice.

    • Daniela Carnevale
    • , Marialuisa Perrotta
    •  & Giuseppe Lembo