Microfabricated Electrode Array Compatible With Optical Imaging of Intrinsic Signals During Somatosensory Stimulation and Cortical Spreading Depression

2006 ◽  
Author(s):  
Jeremy J. Theriot ◽  
Neal Prakash ◽  
Arthur W. Toga ◽  
Y. Sungtaek Ju
Keyword(s):  
Optical Imaging ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Cerebral Blood Volume ◽  
Electrode Array ◽  
Transparent Electrode ◽  
Electrophysiological Recording ◽  
Pathological State ◽  
Somatosensory Stimulation ◽  
Intrinsic Signals

Accurate interpretation of functional brain images requires knowledge of the relationship between neurons and their supporting cells and vasculature. Our understanding of this complex and dynamic system would improve if we measure multiple aspects of brain function simultaneously. We have developed a semi-transparent electrode array which allows for concurrent multi-site electrophysiological recording and high-resolution optical imaging of intrinsic signals. The 8-channel electrode array is fabricated on a transparent glass substrate with platinum recording surfaces. We map stimulus-induced field potentials (evoked potentials) and changes in cerebral blood volume in rat somatosensory cortex. We also examine the evolution of these responses during the neuro-pathological state of cortical spreading depression. We have developed a planar multi-electrode array that is fully compatible with Optical imaging of Intrinsic Signals. It provides a sensitive and reliable tool to use in the study of neurovascular coupling in brain activation.

scholarly journals Cortical spreading depression produces long-term disruption of activity-related changes in cerebral blood volume and neurovascular coupling

2005 ◽  
Vol 10 (1) ◽  
pp. 011004 ◽  
Author(s):  
Michael Guiou ◽  
Sameer Sheth ◽  
Masahito Nemoto ◽  
Melissa Walker ◽  
Nader Pouratian ◽  
...  
Keyword(s):  
Blood Volume ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Cerebral Blood Volume ◽  
Neurovascular Coupling

scholarly journals Parenchymal Spin-Lock fMRI Signals Associated with Cortical Spreading Depression

2014 ◽  
Vol 34 (5) ◽  
pp. 768-775 ◽  
Author(s):  
Joonas A Autio ◽  
Artem Shatillo ◽  
Rashid Giniatullin ◽  
Olli H Gröhn
Keyword(s):  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Cerebral Blood Volume ◽  
High Energy ◽  
Blood Oxygenation ◽  
Acute Ischemia ◽  
High Energy Phosphates ◽  
Ph Change ◽  
Spin Lock ◽  
Fmri Signal

We found novel types of parenchymal functional magnetic resonance imaging (fMRI) signals in the rat brain during large increases in metabolism. Cortical spreading depression (CSD), a self-propagating wave of cellular activation, is associated with several pathologic conditions such as migraine and stroke. It was used as a paradigm to evoke transient neuronal depolarization leading to enhanced energy consumption. Activation of CSD was investigated using spin-lock (SL), diffusion, blood oxygenation level-dependent and cerebral blood volume fMRI techniques. Our results show that the SL-fMRI signal is generated by endogenous parenchymal mechanisms during CSD propagation, and these mechanisms are not associated with hemodynamic changes or cellular swelling. Protein phantoms suggest that pH change alone does not explain the observed SL-fMRI signal changes. However, increased amounts of inorganic phosphates released from high-energy phosphates combined with pH changes may produce SL- power-dependent longitudinal relaxation in the rotating frame ( R1ρ) changes in protein phantoms that are similar to those observed during CSD, as seen before in acute ischemia under our experimental conditions. This links SL-fMRI changes intimately to energy metabolism and supports the use of the SL technique as a new, promising functional approach for noninvasive imaging of metabolic transitions in the active or pathologic brain.

scholarly journals Optical Imaging-Based Guidance of Viral Microinjections and Insertion of a Laminar Electrophysiology Probe Into a Predetermined Barrel in Mouse Area S1BF

2021 ◽  
Vol 15 ◽  
Author(s):  
Victor M. Mocanu ◽  
Amir Shmuel
Keyword(s):  
Cerebral Cortex ◽  
Optical Imaging ◽  
Viral Vectors ◽  
Electrophysiological Recording ◽  
Wide Field ◽  
Functional Modules ◽  
Insertion Depth ◽  
Intrinsic Signals ◽  
Spatial Specificity ◽  
The Brain

Wide-field Optical Imaging of Intrinsic Signals (OI-IS; Grinvald et al., 1986) is a method for imaging functional brain hemodynamic responses, mainly used to image activity from the surface of the cerebral cortex. It localizes small functional modules – such as cortical columns – with great spatial resolution and spatial specificity relative to the site of increases in neuronal activity. OI-IS is capable of imaging responses either through an intact or thinned skull or following a craniotomy. Therefore, it is minimally invasive, which makes it ideal for survival experiments. Here we describe OI-IS-based methods for guiding microinjections of optogenetics viral vectors in proximity to small functional modules (S1 barrels) of the cerebral cortex and for guiding the insertion of electrodes for electrophysiological recording into such modules. We validate our proposed methods by tissue processing of the cerebral barrel field area, revealing the track of the electrode in a predetermined barrel. In addition, we demonstrate the use of optical imaging to visualize the spatial extent of the optogenetics photostimulation, making it possible to estimate one of the two variables that conjointly determine which region of the brain is stimulated. Lastly, we demonstrate the use of OI-IS at high-magnification for imaging the upper recording contacts of a laminar probe, making it possible to estimate the insertion depth of all contacts relative to the surface of the cortex. These methods support the precise positioning of microinjections and recording electrodes, thus overcoming the variability in the spatial position of fine-scale functional modules.

scholarly journals Validating layer-specific VASO across species

2020 ◽  
Author(s):  
Laurentius Renzo Huber ◽  
Benedikt A Poser ◽  
Amanda L Kaas ◽  
Elizabeth J Fear ◽  
Sebastian Desbach ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Neural Activity ◽  
Cerebral Blood Volume ◽  
Fold Increase ◽  
Cortical Layer ◽  
Physiological Parameter ◽  
Reliable Estimate ◽  
List Type ◽  
Somatosensory Stimulation ◽  
Bold Fmri

AbstractCerebral blood volume (CBV) has been shown to be a robust and important physiological parameter for quantitative interpretation of functional (f)MRI, capable of delivering highly localized mapping of neural activity. Indeed, with recent advances in ultra-high-field (>=7T) MRI hardware and associated sequence libraries, it has become possible to capture non-invasive CBV weighted fMRI signals across cortical layers. One of the most widely used approaches to achieve this (in humans) is through vascular-space-occupancy (VASO) fMRI. Unfortunately, the exact contrast mechanisms of layer-dependent VASO fMRI have not been validated and thus interpretation of such data is confounded. Here we cross-validate layer-dependent VASO fMRI contrast in a preclinical rat model using well established (but invasive) imaging methods in response to neuronal activation (somatosensory cortex) and respiratory challenge (hypercapnia). In particular VASO derived CBV measures are directly compared to concurrent measures of total haemoglobin changes from high resolution intrinsic optical imaging spectroscopy (OIS). Through direct comparison of response magnitude, across time, negligible changes in hematocrit ratio during activation (neuronal or vascular) are inferred. Quantified cortical layer profiling is demonstrated and in agreement between both VASO and contrast enhanced fMRI (using monocrystalline iron oxide nanoparticles, MION). Responses show high spatial localisation to layers of cortical excitatory and inhibitory processing independent of confounding large draining veins which hamper BOLD fMRI studies. While we find increased VASO based CBV reactivity (3.1 ± 1.2 fold increase) in humans compared to rats it is demonstrated that this reflects differences in stimulus design rather than confounds of the VASO signal source. Together, our findings confirm that the VASO contrast is indeed a reliable estimate of layer-specific CBV changes. This validation study increases the neuronal interpretability of human layer-dependent fMRI results and should supersede BOLD fMRI as the method of choice in neuroscience application studies.HighlightsOur goal is to validate layer-specific VASO fMRI with gold standard methodsLayer-specific VASO sequences are implemented for 7T imaging in humans and ratsComparisons of VASO, optical imaging, and MION confirm the expected contrast originSomatosensory stimulation in humans and rats reveal the same layer-fMRI signaturesWe confirm that VASO is a valid measure to estimate layer-specific neural activityGraphical abstract

scholarly journals Initial Oligemia with Capillary Flow Stop Followed by Hyperemia during K+-Induced Cortical Spreading Depression in Rats

2005 ◽  
Vol 25 (6) ◽  
pp. 742-747 ◽  
Author(s):  
Minoru Tomita ◽  
Istvan Schiszler ◽  
Yutaka Tomita ◽  
Norio Tanahashi ◽  
Hidetaka Takeda ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Cerebral Blood Volume ◽  
Capillary Flow ◽  
Region Of Interest ◽  
Cell Swelling ◽  
Astroglial Cell ◽  
Initial Flow ◽  
Cyclic Changes

Local cerebral blood volume (CBV) and capillary flow changes in regions of depolarizing neurons during K+-induced cortical spreading depression (CSD) in the cerebral cortex of α-chloralose-urethane-anesthetized rats were examined employing a transillumination (550 nm) video system. Capillary flow was calculated as the reciprocal of mean transit times of blood in pixels of 40 μm × 40 μm, each of which contains a few capillaries. Potassium microinjection into the cortex evoked repetitive wave-ring spreads of oligemia at a speed of ca. 2.33±0.48 mm/min. During the spread of CSD, tracer (either saline or carbon black) was injected into the internal carotid artery. Colocated with the oligemic wave, we detected capillary flow stop as evidenced by disappearance of the hemodilution curves. At any location in the region of interest within the cerebral cortex, we observed cyclic changes of capillary flow stop/hyperperfusion in synchrony with oligemia/hyperemia fluctuations. The initial flow stop and oligemia were ascribed to capillary compression by astroglial cell swelling, presumably at the pericapillary endfeet, since the oligemia occurred before larger vessel changes. We conclude that local depolarizing neurons can decrease adjacent capillary flow directly and immediately, most likely via astroglial cell swelling, and that the flow stop triggers upstream arteriolar dilatation for capillary hyperperfusion.

scholarly journals Mapping optogenetically-driven single-vessel fMRI with concurrent neuronal calcium recordings in the rat hippocampus

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xuming Chen ◽  
Filip Sobczak ◽  
Yi Chen ◽  
Yuanyuan Jiang ◽  
Chunqi Qian ◽  
...  
Keyword(s):  
Spreading Depression ◽  
Cerebral Blood Volume ◽  
Blood Oxygen Level Dependent ◽  
Electrophysiological Recording ◽  
Blood Oxygen Level ◽  
Hemodynamic Responses ◽  
Network Function ◽  
Single Vessel ◽  
Ca1 Region

AbstractExtensive in vivo imaging studies investigate the hippocampal neural network function, mainly focusing on the dorsal CA1 region given its optical accessibility. Multi-modality fMRI with simultaneous hippocampal electrophysiological recording reveal broad cortical correlation patterns, but the detailed spatial hippocampal functional map remains lacking given the limited fMRI resolution. In particular, hemodynamic responses linked to specific neural activity are unclear at the single-vessel level across hippocampal vasculature, which hinders the deciphering of the hippocampal malfunction in animal models and the translation to critical neurovascular coupling (NVC) patterns for human fMRI. We simultaneously acquired optogenetically-driven neuronal Ca2+ signals with single-vessel blood-oxygen-level-dependent (BOLD) and cerebral-blood-volume (CBV)-fMRI from individual venules and arterioles. Distinct spatiotemporal patterns of hippocampal hemodynamic responses were correlated to optogenetically evoked and spreading depression-like calcium events. The calcium event-related single-vessel hemodynamic modeling revealed significantly reduced NVC efficiency upon spreading depression-like (SDL) events, providing a direct measure of the NVC function at various hippocampal states.

Characterization of optical intrinsic signals and blood volume during cortical spreading depression

Neuroreport ◽  
2000 ◽  
Vol 11 (10) ◽  
pp. 2121-2125 ◽  
Author(s):  
Alyssa M. OʼFarrell ◽  
David E. Rex ◽  
Arpitha Muthialu ◽  
Nader Pouratian ◽  
Greg K. Wong ◽  
...  
Keyword(s):  
Blood Volume ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Intrinsic Signals

scholarly journals Cytoarchitecture-Dependent Decrease in Propagation Velocity of Cortical Spreading Depression in the Rat Insular Cortex Revealed by Optical Imaging

2015 ◽  
Vol 26 (4) ◽  
pp. 1580-1589 ◽  
Author(s):  
Satoshi Fujita ◽  
Naoko Mizoguchi ◽  
Ryuhei Aoki ◽  
Yilong Cui ◽  
Noriaki Koshikawa ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Propagation Velocity ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Insular Cortex
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