Intrinsic Optical Signals in Respiratory Brain Stem Regions of Mice: Neurotransmitters, Neuromodulators, and Metabolic Stress

Haller, Miriam; Mironov, S. L.; Richter, Diethelm W.

doi:10.1152/jn.2001.86.1.412

Cited by 29 publications

(19 citation statements)

References 76 publications

(64 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…From the distribution of the changes and their pharmacological modulation, MacVicar and Hochman infer the underlying physiologic process being detected is potassium-related glial swelling, which begins 2 to 3 seconds after stimulus onset, peaks at 6 seconds, and resolves some 20 seconds after stimulus cessation. Intrinsic optical signal changes in response to hypoxia have been attributed to both cell and mitochondrial swelling (Haller et al, 2001), whereas the option to monitor extracellular space by IOS changes in the slice has been established by Witte et al (2001) and Holthoff and Witte (1998). The IOS response to electrical stimulation has been shown to increase linearly with stimulus intensity.…”

Section: Brain Slice Preparationsmentioning

confidence: 99%

Beyond the Visible—Imaging the Human Brain with Light

Obrig

Villringer

2003

J Cereb Blood Flow Metab

549

215

View full text Add to dashboard Cite

Summary:Optical approaches to investigate cerebral function and metabolism have long been applied in invasive studies. From the neuron cultured in vitro to the exposed cortex in the human during neurosurgical procedures, high spatial resolution can be reached and several processes such as membrane potential, cell swelling, metabolism of mitochondrial chromophores, and vascular response can be monitored, depending on the respective preparation. The authors focus on an extension of optical methods to the noninvasive application in the human. Starting with the pioneering work of Jöbsis 25 years ago, nearinfrared spectroscopy (NIRS) has been used to investigate functional activation of the human cerebral cortex. Recently, several groups have started to use imaging systems that allow the generation of images of a larger area of the subject's head and, thereby, the production of maps of cortical oxygenation changes. Such images have a much lower spatial resolution compared with the invasively obtained optical images. The noninvasive NIRS images, however, can be obtained in undemanding set-ups that can be easily combined with other functional methods, in particular EEG. Moreover, NIRS is applicable to bedside use. The authors briefly review some of the abundant literature on intrinsic optical signals and the NIRS imaging studies of the past few years. The weaknesses and strengths of the approach are critically discussed. The authors conclude that NIRS imaging has two major advantages: it can address issues concerning neurovascular coupling in the human adult and can extend functional imaging approaches to the investigation of the diseased brain. Key Words: Near-infrared spectroscopy-Cerebral oxygenation-Vascular imagingNoninvasive.The first investigations into the functional anatomy of the human cerebral cortex were based on lesion studies. The role of specific cortical areas involved in a specific task was inferred by comparing a patient's dysfunction to the lesion seen at autopsy (Fig. 1A). Whereas initially only electrophysiologic techniques allowed noninvasive functional studies of the human brain, the advent of modern imaging techniques such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) have increasingly dominated the field during the past decade. The great advantage is the spatial resolution, which for fMRI is steadily improving and may even allow the differentiation of different cortical layers.There is an increasing need, however, for a better understanding of the signal physiology, in particular of blood oxygenation level-dependent (BOLD) contrast, since the basic principles of the coupling between the neuronal and the vascular response to functional stimulation are still not fully understood (Villringer and Dirnagl, 1995).In the present article we focus on noninvasive imaging approaches in the human using light. Near-infrared spectroscopy (NIRS),* the technique on which such imaging approaches are based, has been covered in previous articles that reviewed its potential...

show abstract

Section: Brain Slice Preparationsmentioning

confidence: 99%

Beyond the Visible—Imaging the Human Brain with Light

Obrig

Villringer

2003

J Cereb Blood Flow Metab

549

215

View full text Add to dashboard Cite

show abstract

“…Influx of Ca 2+ into the cytoplasm causes an increase in the amount of Ca 2+ that affects various enzymes, signaling pathways and cytoskeletal structure [39,40]. This results in complex reorganizations of the cytoplasm and in changes of the local refractive index [5].…”

Section: Cell Visualizationmentioning

confidence: 99%

“…Stepnoski [4] showed that the intensity of light scattered by the mollusc Aplysia neurons depends linearly on the transmembrane potential. It is now clear that the optical properties of the cell (e.g., refractive index) depend not only on the cellular electric activity and ion fluxes but also on the cell volume and shape, and on the location of organelles [5]. It is generally considered, however, that changes in the refractive index mainly relate to events in the plasma membrane.…”

Section: Introductionmentioning

confidence: 99%

Unraveling Cell Processes: Interference Imaging Interwoven with Data Analysis

Brazhe

Pavlov

et al. 2006

J Biol Phys

View full text Add to dashboard Cite

The paper presents results on the application of interference microscopy and wavelet-analysis for cell visualization and studies of cell dynamics. We demonstrate that interference imaging of erythrocytes can reveal reorganization of the cytoskeleton and inhomogenity in the distribution of hemoglobin, and that interference imaging of neurons can show intracellular compartmentalization and submembrane structures. We investigate temporal and spatial variations of the refractive index for different cell types: isolated neurons, mast cells and erythrocytes. We show that the refractive dynamical properties differ from cell type to cell type and depend on the cellular compartment. Our results suggest that low frequency variations (0.1-0.6 Hz) result from plasma membrane processes and that higher frequency variations (20)(21)(22)(23)(24)(25)(26) are related to the movement of vesicles. Using double-wavelet analysis, we study the modulation of the 1 Hz rhythm in neurons and reveal its changes under depolarization and hyperpolarization of the plasma membrane. We conclude that interference microscopy combined with wavelet analysis is a useful technique for non-invasive cell studies, cell visualization, and investigation of plasma membrane properties.

show abstract

“…It is known that changes of the neuronal intrinsic optical properties are caused by cellular electric activity, redistribution of intra-and extra-cellular ions, and changes of the volume, shape, and location of various organelles [9,10]. So far, however, the temporal properties of these processes and their mutual interdependences have remained practically unexplored.…”

mentioning

confidence: 99%