scholarly journals Multi-parametric characterization of brain-wide hemodynamic and calcium responses to sensory stimulation in mice

2021 ◽  
Author(s):  
Zhenyue Chen ◽  
Quanyu Zhou ◽  
Xose Luis Dean-Ben ◽  
Irmak Gezginer ◽  
Ruiqing Ni ◽  
...  
Keyword(s):  
Functional Neuroimaging ◽  
Statistical Parametric Mapping ◽  
Sensory Stimulation ◽  
Activation Patterns ◽  
Hemoglobin Oxygen Saturation ◽  
Optoacoustic Tomography ◽  
Peripheral Sensory ◽  
Coupling Mechanisms ◽  
Single Modality

Modern optical neuroimaging approaches are expanding our ability to elucidate complex brain function. Diverse imaging contrasts enable direct observation of neural activity with functional sensors along with the induced hemodynamic responses. To date, decoupling the complex interplay of neurovascular coupling and dynamical physiological states has remained challenging when employing single-modality functional neuroimaging tools. We devised a hybrid fluorescence optoacoustic tomography (FLOT) platform combined with a custom data processing pipeline based on statistical parametric mapping, accomplishing the first simultaneous noninvasive observation of both direct and indirect brain-wide activation patterns with optical contrast. Correlated changes in the oxy- and deoxygenated hemoglobin, total hemoglobin, oxygen saturation and rapid GCaMP6f fluorescence signals were observed in response to peripheral sensory stimulation. While the concurrent epifluorescence served to corroborate and complement the functional optoacoustic observations, the latter further aided in decoupling the rapid calcium responses from the slowly varying background in the fluorescence recordings mediated by hemodynamic changes. The hybrid imaging platform expands the capabilities of conventional neuroimaging methods to provide more comprehensive functional readings for studying neurovascular and neurometabolic coupling mechanisms and related diseases.

Effects of Psychotherapy on Brain Activation Patterns in Anxiety Disorders

2016 ◽  
Vol 224 (2) ◽  
pp. 62-70 ◽  
Author(s):  
Thomas Straube
Keyword(s):  
Anxiety Disorders ◽  
Neuronal Plasticity ◽  
Functional Neuroimaging ◽  
State Of The Art ◽  
Methodological Issues ◽  
Future Directions ◽  
Activation Patterns ◽  
New Learning ◽  
Analytical Strategies ◽  
Sample Characteristics

Abstract. Psychotherapy is an effective treatment for most mental disorders, including anxiety disorders. Successful psychotherapy implies new learning experiences and therefore neural alterations. With the increasing availability of functional neuroimaging methods, it has become possible to investigate psychotherapeutically induced neuronal plasticity across the whole brain in controlled studies. However, the detectable effects strongly depend on neuroscientific methods, experimental paradigms, analytical strategies, and sample characteristics. This article summarizes the state of the art, discusses current theoretical and methodological issues, and suggests future directions of the research on the neurobiology of psychotherapy in anxiety disorders.

scholarly journals Evidence that the TRPV1 S1-S4 Membrane Domain Contributes to Thermosensing

2019 ◽  
Author(s):  
Minjoo Kim ◽  
Nicholas J. Sisco ◽  
Jacob K. Hilton ◽  
Camila M. Montano ◽  
Manuel A. Castro ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Solution Nmr ◽  
Membrane Domain ◽  
Temperature Dependent ◽  
Nmr Characterization ◽  
Significant Interest ◽  
Pore Domain ◽  
Coupling Mechanisms

AbstractSensing and responding to temperature is crucial in biology. The TRPV1 ion channel is a well-studied heat-sensing receptor that is also activated by vanilloid compounds including capsaicin. Despite significant interest, the molecular underpinnings of thermosensing have remained elusive. The TRPV1 S1-S4 membrane domain couples chemical ligand binding to the pore domain during channel gating. However, the role of the S1-S4 domain in thermosensing is unclear. Evaluation of the isolated human TRPV1 S1-S4 domain by solution NMR, Far-UV CD, and intrinsic fluorescence shows that this domain undergoes a non-denaturing temperature-dependent transition with a high thermosensitivity. Further NMR characterization of the temperature-dependent conformational changes suggests the contribution of the S1-S4 domain to thermosensing shares features with known coupling mechanisms between this domain with ligand and pH activation. Taken together, this study shows that the TRPV1 S1-S4 domain contributes to TRPV1 temperature-dependent activation.

scholarly journals Fine Tuning of Redox Networks on Multiheme Cytochromes fromGeobacter sulfurreducensDrives Physiological Electron/Proton Energy Transduction

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Leonor Morgado ◽  
Joana M. Dantas ◽  
Marta Bruix ◽  
Yuri Y. Londer ◽  
Carlos A. Salgueiro
Keyword(s):  
Microbial Fuel Cells ◽  
Geobacter Sulfurreducens ◽  
Cellular Growth ◽  
Bohr Effect ◽  
Fine Tuning ◽  
Physiological Relevance ◽  
Ph Range ◽  
Coupling Mechanisms ◽  
Redox Bohr Effect

The bacteriumGeobacter sulfurreducens (Gs)can grow in the presence of extracellular terminal acceptors, a property that is currently explored to harvest electricity from aquatic sediments and waste organic matter into microbial fuel cells. A family composed of five triheme cytochromes (PpcA-E) was identified inGs. These cytochromes play a crucial role by bridging the electron transfer from oxidation of cytoplasmic donors to the cell exterior and assisting the reduction of extracellular terminal acceptors. The detailed thermodynamic characterization of such proteins showed that PpcA and PpcD have an important redox-Bohr effect that might implicate these proteins in the e−/H+coupling mechanisms to sustain cellular growth. The physiological relevance of the redox-Bohr effect in these proteins was studied by determining the fractional contribution of each individual redox-microstate at different pH values. For both proteins, oxidation progresses from a particular protonated microstate to a particular deprotonated one, over specific pH ranges. The preferred e−/H+transfer pathway established by the selected microstates indicates that both proteins are functionally designed to couple e−/H+transfer at the physiological pH range for cellular growth.

scholarly journals Effector-Specific Characterization of Brain Dynamics in Manual vs. Oculomotor Go/NoGo Tasks

2020 ◽  
Vol 14 ◽  
Author(s):  
Marie Simonet ◽  
Paolo Ruggeri ◽  
Jérôme Barral
Keyword(s):  
Stimulus Onset ◽  
Brain Dynamics ◽  
Activation Patterns ◽  
Topographic Analysis ◽  
Attentional Processes ◽  
Wide Range ◽  
Healthy Young People ◽  
Oculomotor Response ◽  
Different Response

Motor inhibitory control (IC), the ability to suppress unwanted actions, has been previously shown to rely on domain-general IC processes that are involved in a wide range of IC tasks. Nevertheless, the existence of effector-specific regions and activation patterns that would differentiate manual vs. oculomotor response inhibition remains unknown. In this study, we investigated the brain dynamics supporting these two response effectors with the same IC task paradigm. We examined the behavioral performance and electrophysiological activity in a group of healthy young people (n = 25) with a Go/NoGo task using the index finger for the manual modality and the eyes for the oculomotor modality. By computing topographic analysis of variance, we found significant differences between topographies of scalp recorded potentials of the two response effectors between 250 and 325 ms post-stimulus onset. The source estimations localized this effect within the left precuneus, a part of the superior parietal lobule, showing stronger activity in the oculomotor modality than in the manual modality. Behaviorally, we found a significant positive correlation in response time between the two modalities. Our collective results revealed that while domain-general IC processes would be engaged across different response effectors in the same IC task, effector-specific activation patterns exist. In this case, the stronger activation of the left precuneus likely accounts for the increased demand for visual attentional processes in the oculomotor Go/NoGo task.

Somatosensory cortical efferent neurons of the awake rabbit: latencies to activation via supra--and subthreshold receptive fields

1996 ◽  
Vol 75 (4) ◽  
pp. 1753-1759 ◽  
Author(s):  
H. A. Swadlow ◽  
T. P. Hicks
Keyword(s):  
High Speed ◽  
Receptive Fields ◽  
Cortical Cell ◽  
Sensory Stimulation ◽  
Inhibitory Response ◽  
Postsynaptic Potentials ◽  
Peripheral Stimulation ◽  
Efferent Neurons ◽  
Excitatory Component ◽  
Peripheral Sensory

1. Latencies to peripheral sensory stimulation were examined in four classes of antidromically identified efferent neurons in the primary somatosensory cortex (S1) of awake rabbits. Both suprathreshold responses (action potentials) and subthreshold responses were examined. Subthreshold responses were examined by monitoring the thresholds of efferent neurons to juxtasomal current pulses (JSCPs) delivered through the recording microelectrode (usually 1-3 microA). Through the use of this method, excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) were manifested as decreases and increases in threshold, respectively. Efferent populations examined included callosal (CC) neurons, ipsilateral corticocortical (C-IC) neurons, and descending corticofugal neurons of layer 5 (CF-5) and layer 6 (CF-6). Very brief air puffs (rise and fall times 0.6 ms) were delivered to the receptor periphery via a high-speed solenoid valve. 2. Whereas all CF-5 neurons had demonstrable suprathreshold excitatory and/or inhibitory responses to peripheral stimulation, most CC, C-IC, and CF-6 neurons did not. CC and CF-6 neurons that yielded no suprathreshold response to the stimulus had lower axonal conduction velocities than those that did respond (P < 0.0001 in both cases). However, subthreshold receptive fields could be demonstrated in many of the otherwise unresponsive CC (81%), C-IC (88%), and CF-6 (43%) neurons. The subthreshold responses usually consisted of an initial excitatory component (a decrease in the threshold to the JSCP) and a subsequent long-duration (> 80 ms) inhibitory component. A few neurons (1 CC, 1 C-IC, and 5 CF-6) showed an initial short latency inhibitory response in the absence of any excitatory component. 3. Some CC and C-IC neurons yielded supra- and/or subthreshold responses to peripheral stimulation at latencies of 6.1-7 ms. All such neurons were found at intermediate cortical depths (thought to correspond to deep layer 2-3 through layer 5). It is argued that such latencies are indicative of monosynaptic activation via thalamic afferents. Very superficial CC and C-IC neurons, and all CF-6 neurons responded to latencies of > 7 ms. All CF-5 neurons responded to latencies of > 8 ms, although many were found at the same depth as the deeper CC and C-IC neurons that responded at monosynaptic latencies. These results indicate that cortical cell type as well as laminar position are important factors that determine the sequence of intracortical neuronal activation after peripheral sensory stimulation.

scholarly journals Mapping-guided characterization of mechanical and electrical activation patterns in patients with normal systolic function using a sensor-based tracking technology

EP Europace ◽  
2016 ◽  
pp. euw261 ◽  
Author(s):  
Christopher Piorkowski ◽  
Ole-A. Breithardt ◽  
Hedi Razavi ◽  
Yelena Nabutovsky ◽  
Stuart P. Rosenberg ◽  
...  
Keyword(s):  
Systolic Function ◽  
Electrical Activation ◽  
Activation Patterns ◽  
Normal Systolic Function ◽  
Tracking Technology

Abstract 4301: Detection and characterization of regions of hypoxia within orthotopic pancreatic tumors using multispectral optoacoustic tomography

2014 ◽  
Author(s):  
Shanice V. Hudson ◽  
Charles Kimbrough ◽  
Michael Egger ◽  
Anil Khanal ◽  
Michelle E. Smith ◽  
...  
Keyword(s):  
Pancreatic Tumors ◽  
Optoacoustic Tomography

Migraine and Other Headache Disorders

2017 ◽  
Author(s):  
Robert W. Charlson ◽  
Matthew S. Robbins
Keyword(s):  
Functional Neuroimaging ◽  
Specific Treatment ◽  
Peripheral Sensitization ◽  
Headache Disorders ◽  
Key Factors ◽  
Complex Disorder ◽  
Calcitonin Gene ◽  
Neuroimaging Techniques

In recent years, the characterization of the neurobiology of migraine and other headache disorders has been driven by the search to better understand several key factors: genetics, the role of neuromodulators such as calcitonin gene-related peptide (CGRP), processes including central and peripheral sensitization, neurogenic inflammation, central pain networks, and areas of activation demonstrated by advancing functional neuroimaging techniques. Yet the ultimate causes of migraine remain unknown. Nonetheless, recent work has advanced our understanding of this complex disorder, and pointed toward a future where these modalities may provide an integrated understanding of its pathophysiology and provide specific treatment targets.

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