Springer protocols feed by Neuroscience 
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This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.Neurovascular Coupling in Relation to Cortical Spreading Depression
Cortical spreading depression (SD) has been known for more than 70 years. It has been a unique method investigating basic neurophysiology. A growing body of evidence indicates SD is involved in clinical conditions such as migraine with aura, subarachnoid hemorrhage, and traumatic brain injury. In this chapter we describe the application of SD in studying neurovascular and neurometabolic coupling in rat cerebral cortex. Description of the different techniques (electrophysiology, laser-Doppler flowmetry, and oxygen-sensitive electrodes) is followed by in depth step-by-step instructions on how to use them. This chapter will a...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Closed Cranial Window Applications in the Rat: Studies on Neurovascular Coupling Involving Pial Arterioles and the Glia Limitans
Because of their intimate anatomic relationship with cerebral arterioles and neurons, astrocytes have been postulated to function as signal transducers, transferring information from activated neurons to the cerebral microcirculation. The above is labelled as “neurovascular coupling” and its components (i.e., neuron, astrocyte, and vascular cells) as the “neurovascular unit (NVU).” In the brain, NVUs can take a variety of forms. In the chapter, we highlight a well-represented cortical NVU consisting of pial arterioles, the glia limitans, and cortical neurons. This particular NVU can be readily exami...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Noninvasive Laser-Induced Photoacoustic Tomography for Functional Imaging
We present in detail photoacoustic reconstruction methods and imaging systems. Using a rodent model of acute focal epilepsy, we demonstrate the noninvasive yet whole surface and depth capabilities of the PAT system that allow to actually see what is happening during ictogenesis in terms of seizure onset and spread. Both seizure onset and propagation are tomographically detected at a spatial resolution of 150 μm and a temporal resolution of 300 ms. Dynamical changes of vasculature during epileptiform events are also detected with high spatiotemporal resolution. Together, these findings suggest that PAT represents a power...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Simultaneous Multi-Wavelength Optical Imaging of Neuronal and Hemodynamic Activity
Functional brain imaging techniques, such as functional magnetic resonance imaging, infer changes in underlying neural activity from perfusion-related signals and can be sampled from large areas of cortex to examine hemodynamic network activity. However, measurement of the underlying neuronal activity in a correspondingly widespread network is not available for comparison. In order to accurately understand the origins of these hemodynamic signals and the mechanisms of neurovascular coupling, it is critical to be able to measure widespread neuronal activity simultaneously and homotopically with the vascular signal. For this...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Physiological Basis of BOLD fMRI Decreases
Recent studies suggest that positive functional magnetic resonance imaging (fMRI) signal changes in the cortex under normal physiological conditions are closely related to increased neuronal activity. However, the physiological basis of negative blood oxygen level-dependent (BOLD) fMRI signal changes in the cortex as well as in subcortical structures are less well understood. Animal models that employ combined neuroimaging and direct electrophysiological measurements provide a powerful avenue for studying the complex relationships between negative fMRI changes and neuronal activity under normal and abnormal conditions (suc...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Multi-Spectral Imaging of Blood Volume, Metabolism, Oximetry, and Light Scattering
Advances in functional imaging techniques including fMRI, PET, and SPECT have improved our understanding of the relationship between brain activity and brain energy supply. Neurovascular and neurometabolic coupling are critical to supply the energy demands of brain tissue during both normal physiological function and pathological conditions. With the use of multi-spectral imaging techniques, one can simultaneously measure changes in cerebral blood volume, oxyhemoglobin, deoxyhemoglobin, light scattering, and local metabolism during epilepsy. (Source: Springer protocols feed by Neuroscience)
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Optical Intrinsic Signal Imaging for Elucidating Functional Structures in Higher Visual Area
To understand neural mechanisms of object recognition, representation of visual object images has been studied in inferior temporal (IT) cortex, which is located at the final stage of the ventral object recognition pathway. Optical intrinsic signal imaging (OISI) is a powerful imaging technique to visualize spatial patterns of object representation in IT cortex. In this chapter, we will describe technical procedures of OISI particularly required when applying to IT cortex, and also recent advancement with OISI in understanding object representation and functional organization of IT cortex. (Source: Springer protocols feed by Neuroscience)
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
High-Resolution Wide-Field Optical Imaging of Microvascular Characteristics: From the Neocortex to the Eye
Measuring microvascular characteristics in cortical tissue and individual microvessels has important applications for functional imaging, biomedical research, and clinical diagnostics. Multiphoton fluorescence microscopy approaches are most effective and allow to reliably record red blood cell (RBC) velocity in individual vessels, but require injecting fluorescent tracers. Moreover, only one or few vessels in a small area can be imaged at a time. Wide-field CCD/CMOS-based optical imaging of intrinsic absorption or reflection changes in macroscopic vascular networks allows to overcome these shortcomings, by recording RBCs&r...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Noninvasive Neural Imaging and Tissue Oxygenation in the Visual System
Noninvasive functional magnetic resonance imaging (fMRI) has become a primary tool for the measurement of behavior-related neural activity in the human brain. However, the blood oxygen level-dependent (BOLD) signal used in fMRI does not directly measure neural activity. It measures hemodynamic local changes in deoxygenated hemoglobin. To understand the functional significance of these changes, local tissue oxygen concentration may be measured as a way of studying dynamic oxygenation in the brain. Here, we use a dual-purpose sensor to simultaneously measure changes in tissue oxygenation and neural activity in the central vi...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Neurovascular Coupling in the Deep Brain Using Confocal Fiber-Optic Endomicroscopy
Developing fast functional imaging approaches of subcortical structures is essential to make progress in our understanding of brain function and diseases. Positron emission tomography and functional magnetic resonance imaging have been used to improve our understanding of brain function and integration of neuronal activity between deeper structures and the superficial cortex but limitations remain associated with signal interpretation. This work describes the design and utilization of confocal microendoscopy techniques to image brain structures involved in visual processing, either deep or on the surface of the cortex. Als...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Imaging Vasodynamics in the Awake Mouse Brain with Two-Photon Microscopy
In vivo two-photon laser-scanning microscopy is widely used to study brain structure and function in mice. Recent studies using awake mice have revealed a rich dynamism in cerebrovascular flow and neural activity that is significantly masked by anesthesia. Imaging of awake animals is necessary to fully understand neurovascular coupling during naturalistic sensorimotor activity. We provide detailed instructions to rigorously quantify blood flow at the level of single cortical vessels in awake mice. This includes a description of surgical techniques to obtain optical access to the cortex, improved head-restraint devices to r...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Studying Adenosine and Cerebral Blood Flow (CBF) Using Pharmacological Methods
The authors review the use of pharmacological agents to investigate in rodents the role of adenosine (Ado) in the regulation of cerebral blood flow (CBF). Two techniques are highlighted: an in vitro preparation using perfused and pressurized penetrating brain arterioles (the PPP Prep) and in vivo cranial window preparation utilized to study CBF during neuronal activation evoked by contralateral sciatic nerve stimulation. Materials, Methods, and Notes are provided, as well as a data illustrating the utility and power of these techniques. (Source: Springer protocols feed by Neuroscience)
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Neurovascular Coupling Investigated by Simultaneous Optical Coherence Tomography and Electrophysiology
A comprehensive understanding of the neurovascular coupling relationship requires the simultaneous measurement of neuronal and vascular responses and the capability to probe all layers of the cerebral cortex. Current macroscopic imaging techniques like laser Doppler imaging, diffuse optical tomography, fMRI, and PET lack spatial resolution. While two-photon microscopy is widely used in imaging the brain, it suffers from a lack of depth penetration and imaging speed. Optical coherence tomography (OCT) provides a platform for imaging the brain that potentially overcomes all of the above disadvantages, providing high-resoluti...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Simultaneous Functional Magnetic Resonance and Two-Dimensional Optical Imaging Spectroscopy
The blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal is a biophysical consequence of the hemodynamic response to neuronal activity. Intrinsic optical imaging spectroscopy (2D-OIS) is an invasive imaging method that can provide detailed two-dimensional information of this underlying hemodynamic response. Here, methods for the combination of fMRI and 2D-OIS in the rodent model are described. One of the numerous advantages of this simultaneous methodology is that 2D-OIS provides an independent hemodynamic measure to help interpret evoked or spontaneous BOLD signals. This is importan...
Source: Springer protocols feed by Neuroscience - May 6, 2014 Category: Neuroscience Source Type: news
Hypoxia-Induced Angiogenesis and Capillary Density Determination
Chronic exposure to moderate hypoxia elicits structural and functional changes in the microvascular network of the mammalian CNS. Hypoxia-induced angiogenesis can be elicited and studied by a relatively simple experimental method. Rats or mice can be exposed to mild hypoxia in a hypobaric chamber, or alternatively in a normobaric hypoxia chamber. After 3 weeks, the animals are perfused and fixed, the brain removed, and paraffin embedded and sectioned at 5 μm. The sections are stained for the blood-brain barrier glucose transporter (GLUT-1) by immunohistochemistry, capillary profiles identified and counted as a measure o...
Source: Springer protocols feed by Neuroscience - February 12, 2014 Category: Neuroscience Source Type: news
