Dataset Information

Dynamics of the cerebral blood flow response to brief neural activity in human visual cortex.

ABSTRACT: The blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal depends on an interplay of cerebral blood flow (CBF), oxygen metabolism, and cerebral blood volume. Despite wide usage of BOLD fMRI, it is not clear how these physiological components create the BOLD signal. Here, baseline CBF and its dynamics evoked by a brief stimulus (2 s) in human visual cortex were measured at 3T. We found a stereotypical CBF response: immediate increase, rising to a peak a few second after the stimulus, followed by a significant undershoot. The BOLD hemodynamic response function (HRF) was also measured in the same session. Strong correlations between HRF and CBF peak responses indicate that the flow responses evoked by neural activation in nearby gray matter drive the early HRF. Remarkably, peak CBF and HRF were also strongly modulated by baseline perfusion. The CBF undershoot was reliable and significantly correlated with the HRF undershoot. However, late-time dynamics of the HRF and CBF suggest that oxygen metabolism can also contribute to the HRF undershoot. Combined measurement of the CBF and HRF for brief neural activation is a useful tool to understand the temporal dynamics of neurovascular and neurometabolic coupling.

SUBMITTER: Kim JH

PROVIDER: S-EPMC7446561 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Dynamics of the cerebral blood flow response to brief neural activity in human visual cortex.

Kim Jung Hwan JH Taylor Amanda J AJ Wang Danny Jj DJ Zou Xiaowei X Ress David D

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 20190820 9

The blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal depends on an interplay of cerebral blood flow (CBF), oxygen metabolism, and cerebral blood volume. Despite wide usage of BOLD fMRI, it is not clear how these physiological components create the BOLD signal. Here, baseline CBF and its dynamics evoked by a brief stimulus (2 s) in human visual cortex were measured at 3T. We found a stereotypical CBF response: immediate increase, rising to a peak a few secon ...[more]

PMID: 31429358

Similar Datasets

Project description:Cocaine affects both cerebral blood vessels and neuronal activity in brain. Cocaine can also disrupt astrocytes, which modulate neurovascular coupling-a process that regulates cerebral hemodynamics in response to neuronal activation. However, separating neuronal and astrocytic effects from cocaine's direct vasoactive effects has been challenging, partially due to limitations of neuroimaging techniques able to differentiate vascular from neuronal and glial effects at high temporal and spatial resolutions. Here, we used a newly-developed multi-channel fluorescence and optical coherence Doppler microscope (fl-ODM) that allows for simultaneous measurements of neuronal and astrocytic activities (reflected by the intracellular calcium changes in neurons Ca2+N and astrocytes Ca2+A, respectively) alongside their vascular interactions in vivo to address this challenge. Using green and red genetically-encoded Ca2+ indicators differentially expressed in astrocytes and neurons, fl-ODM enabled concomitant imaging of large-scale astrocytic and neuronal Ca2+ fluorescence and 3D cerebral blood flow velocity (CBFv) in vascular networks in the mouse cortex. We assessed cocaine's effects in the prefrontal cortex (PFC) and found that the CBFv changes triggered by cocaine were temporally correlated with astrocytic Ca2+A activity. Chemogenetic inhibition of astrocytes during the baseline state resulted in blood vessel dilation and CBFv increases but did not affect neuronal activity, suggesting modulation of spontaneous blood vessel's vascular tone by astrocytes. Chemogenetic inhibition of astrocytes during a cocaine challenge prevented its vasoconstricting effects alongside the CBFv decreases, but it also attenuated the neuronal Ca2+N increases triggered by cocaine. These results document a role of astrocytes both in regulating vascular tone and consequently blood flow, at baseline and for modulating the vasoconstricting and neuronal activation responses to cocaine in the PFC. Strategies to inhibit astrocytic activity could offer promise for ameliorating vascular and neuronal toxicity from cocaine misuse.

Dataset Information

Dynamics of the cerebral blood flow response to brief neural activity in human visual cortex.

Publications

Dynamics of the cerebral blood flow response to brief neural activity in human visual cortex.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets