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https://www.readbyqxmd.com/read/29890297/nociception-pain-consciousness-and-society-a-plea-for-constrained-use-of-pain-related-terminologies
#1
A Vania Apkarian
This focus article addresses the issue of the proper use of terminology in pain research. A review and some revisions on the definitions of pain and nociception, in relation to consciousness is presented. From a behavioral viewpoint, it is argued that pain is a conscious assessment of the failure of the organism to protect the body from injury (actual or potential); while continuously-ongoing sub/pre-conscious nociceptive processes protect the body from injuries. Thus, pain perception/behavior requires a subjective ability to evaluate the environment and form coordinated responses...
June 8, 2018: Journal of Pain: Official Journal of the American Pain Society
https://www.readbyqxmd.com/read/29883101/ultrafast-microscopy-of-spin-momentum-locked-surface-plasmon-polaritons
#2
Yanan Dai, Maciej Dabrowski, Vartkess Ara Apkarian, Hrvoje Petek
Using two-photon photoemission electron microscopy (2P-PEEM) we image the polarization dependence of coupling and propagation of surface plasmon polaritons (SPPs) launched from edges of a triangular, micron size, single crystalline Ag crystal by linearly or circularly polarized light. 2P-PEEM records interferences between the optical excitation field and SPPs it creates with nano-femto space-time resolution. Both the linearly and circularly polarized femtosecond light pulses excite spatially asymmetric 2PP yield distributions, which are imaged...
June 8, 2018: ACS Nano
https://www.readbyqxmd.com/read/29782171/bias-dependent-chemical-enhancement-and-non-classical-stark-effect-in-tip-enhanced-raman-spectromicroscopy-of-co-terminated-ag-tips
#3
Rebecca L M Gieseking, Joonhee Lee, Nicholas Tallarida, Vartkess Ara Apkarian, George C Schatz
Tip-enhanced Raman spectromicroscopy (TERS) with CO-terminated plasmonic tips can probe Ångstrom-scale features of molecules on surfaces. The development of this technique requires understanding of how chemical environments affect the CO vibrational frequency and TERS intensity. At the scanning tunneling microscope junction of a CO-terminated Ag tip, we show that rather than the classical vibrational Stark effect, the large bias dependence of the CO frequency shift is due to ground-state charge transfer from the Ag tip into the CO π* orbital softening the C-O bond at more positive biases...
May 21, 2018: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29417694/inferring-distinct-mechanisms-in-the-absence-of-subjective-differences-placebo-and-centrally-acting-analgesic-underlie-unique-brain-adaptations
#4
Pascal Tétreault, Marwan N Baliki, Alexis T Baria, William R Bauer, Thomas J Schnitzer, A Vania Apkarian
Development and maintenance of chronic pain is associated with structural and functional brain reorganization. However, few studies have explored the impact of drug treatments on such changes. The extent to which long-term analgesia is related to brain adaptations and its effects on the reversibility of brain reorganization remain unclear. In a randomized placebo-controlled clinical trial, we contrasted pain relief (3-month treatment period), and anatomical (gray matter density [GMD], assessed by voxel-based morphometry) and functional connectivity (resting state fMRI nodal degree count [DC]) adaptations, in 39 knee osteoarthritis (OA) patients (22 females), randomized to duloxetine (DLX, 60 mg once daily) or placebo...
May 2018: Human Brain Mapping
https://www.readbyqxmd.com/read/29353539/translation-and-validation-of-simplified-chinese-version-of-the-pain-catastrophizing-scale-in-chronic-pain-patients-education-may-matter
#5
Bangli Shen, Bo Wu, Taha B Abdullah, Gonghao Zhan, Qingquan Lian, Apkar Vania Apkarian, Lejian Huang
Objective Pain catastrophizing is linked to many aspects of pain perception and defines a unique dimension in predicting pain intensity and physical disability. Pain Catastrophizing Scale (PCS) is an effective, validated,self-report measure, commonly used in clinical trials. Here, we present a Simplified Chinese PCS (SC-PCS) version developed in Chinese patients suffering from chronic pain. Methods The SC-PCS was generated in five steps and tested on an initial patient cohort (N = 30). A convenience sample (N = 200) of in-hospital patients with non-malignant pain lasting for more than 12 weeks were recruited for the study, of which 81 completed 5 additional pain questionnaires...
January 2018: Molecular Pain
https://www.readbyqxmd.com/read/29212921/bold-temporal-variability-differentiates-wakefulness-from-anesthesia-induced-unconsciousness
#6
Alexis T Baria, Maria V Centeno, Mariam E Ghantous, Pei C Chang, Daniele Procissi, A Vania Apkarian
Even though a number of findings, based on information content or information integration, are shown to define neural underpinnings characteristic of a conscious experience, the neurophysiological mechanism of consciousness is still poorly understood. Here, we investigated the brain activity and functional connectivity changes that occur in the isoflurane-anesthetized unconscious state in contrast to the awake state in rats (awake and/or anesthetized, n = 68 rats). We examined nine information measures previously shown to distinguish between conscious states: blood oxygen level-dependent (BOLD) variability, functional connectivity strength, modularity, weighted modularity, efficiency, clustering coefficient, small-worldness, and spatial and temporal Lempel-Ziv complexity measure...
March 1, 2018: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29080714/hippocampal-morphology-mediates-biased-memories-of-chronic-pain
#7
Sara E Berger, Étienne Vachon-Presseau, Taha B Abdullah, Alex T Baria, Thomas J Schnitzer, A Vania Apkarian
Experiences and memories are often mismatched. While multiple studies have investigated psychological underpinnings of recall error with respect to emotional events, the neurobiological mechanisms underlying the divergence between experiences and memories remain relatively unexplored in the domain of chronic pain. Here we examined the discrepancy between experienced chronic low back pain (CBP) intensity (twice daily ratings) and remembered pain intensity (n = 48 subjects) relative to psychometric properties, hippocampus morphology, memory capabilities, and personality traits related to reward...
February 1, 2018: NeuroImage
https://www.readbyqxmd.com/read/29080228/morphology-of-subcortical-brain-nuclei-is-associated-with-autonomic-function-in-healthy-humans
#8
James K Ruffle, Steven J Coen, Vincent Giampietro, Steven C R Williams, A Vania Apkarian, Adam D Farmer, Qasim Aziz
The autonomic nervous system (ANS) is a brain body interface which serves to maintain homeostasis by influencing a plethora of physiological processes, including metabolism, cardiorespiratory regulation and nociception. Accumulating evidence suggests that ANS function is disturbed in numerous prevalent clinical disorders, including irritable bowel syndrome and fibromyalgia. While the brain is a central hub for regulating autonomic function, the association between resting autonomic activity and subcortical morphology has not been comprehensively studied and thus was our aim...
January 2018: Human Brain Mapping
https://www.readbyqxmd.com/read/28990559/-predicting-placebo-response-with-functional-magnetic-resonance-imaging
#9
Pascal Tétreault, A Vania Apkarian
No abstract text is available yet for this article.
June 2017: Médecine Sciences: M/S
https://www.readbyqxmd.com/read/28980800/tip-enhanced-raman-spectromicroscopy-on-the-angstrom-scale-bare-and-co-terminated-ag-tips
#10
Nicholas Tallarida, Joonhee Lee, Vartkess Ara Apkarian
The tip is key to the successful execution of tip-enhanced Raman scattering (TERS) measurements in the single molecule limit. We show that nanoscopically smooth silver tips, batch produced through field-directed sputter sharpening, reliably attain TERS with enhancement factors that reach 1013 , as measured by the Raman spectra of single CO molecules attached to the tip apex. We validate the bare tips by demonstrating spectromicroscopy with submolecular spatial resolution and underscore that TERS is a near-field effect that does not obey simple selection rules...
November 28, 2017: ACS Nano
https://www.readbyqxmd.com/read/28976739/observation-of-single-molecule-plasmon-driven-electron-transfer-in-isotopically-edited-4-4-bipyridine-gold-nanosphere-oligomers
#11
Emily A Sprague-Klein, Michael O McAnally, Dmitry V Zhdanov, Alyssa B Zrimsek, Vartkess A Apkarian, Tamar Seideman, George C Schatz, Richard P Van Duyne
We clarify mechanistic questions regarding plasmon-driven chemistry and nanoscale photocatalysis within optically confined near-field plasmonic systems. Using surface-enhanced Raman scattering (SERS), we directly monitor the photoinduced reaction dynamics of 4,4'-bipyridine molecules, localized in plasmonic hot spots within individual gold nanosphere oligomers. Our experiment generates surface electrons from the gold nanoparticle using an intense off-molecular resonance continuous wave pump field, and detects radical anion products via SERS...
October 13, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28976729/tip-enhanced-raman-spectromicroscopy-of-co-ii-tetraphenylporphyrin-on-au-111-toward-the-chemists-microscope
#12
Joonhee Lee, Nicholas Tallarida, Xing Chen, Pengchong Liu, Lasse Jensen, Vartkess Ara Apkarian
Atomically terminated and nanoscopically smooth silver tips effectively focus light on the angstrom scale, allowing tip-enhanced Raman spectromicroscopy (TER-sm) with single molecule sensitivity and submolecular spatial resolution. Through measurements carried out on cobalt-tetraphenylporphyrin (CoTPP) adsorbed on Au(111), we highlight peculiarities of vibrational spectromicroscopy with light confined on the angstrom scale. Field-gradient-driven spectra, orientational fingerprinting, and sculpting of local fields by atomic morphology of the junction are elucidated through measurements that range from 2D arrays at room temperature to single molecule manipulations at 5 K...
November 28, 2017: ACS Nano
https://www.readbyqxmd.com/read/28692006/brain-signature-and-functional-impact-of-centralized-pain-a-multidisciplinary-approach-to-the-study-of-chronic-pelvic-pain-mapp-network-study
#13
MULTICENTER STUDY
Jason J Kutch, Eric Ichesco, Johnson P Hampson, Jennifer S Labus, Melissa A Farmer, Katherine T Martucci, Timothy J Ness, Georg Deutsch, A Vania Apkarian, Sean C Mackey, David J Klumpp, Anthony J Schaeffer, Larissa V Rodriguez, Karl J Kreder, Dedra Buchwald, Gerald L Andriole, H Henry Lai, Chris Mullins, John W Kusek, J Richard Landis, Emeran A Mayer, J Quentin Clemens, Daniel J Clauw, Richard E Harris
Chronic pain is often measured with a severity score that overlooks its spatial distribution across the body. This widespread pain is believed to be a marker of centralization, a central nervous system process that decouples pain perception from nociceptive input. Here, we investigated whether centralization is manifested at the level of the brain using data from 1079 participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network (MAPP) study. Participants with a clinical diagnosis of urological chronic pelvic pain syndrome (UCPPS) were compared to pain-free controls and patients with fibromyalgia, the prototypical centralized pain disorder...
October 2017: Pain
https://www.readbyqxmd.com/read/28634321/a-central-mechanism-enhances-pain-perception-of-noxious-thermal-stimulus-changes
#14
B Petre, P Tetreault, V A Mathur, M W Schurgin, J Y Chiao, L Huang, A V Apkarian
Pain perception temporarily exaggerates abrupt thermal stimulus changes revealing a mechanism for nociceptive temporal contrast enhancement (TCE). Although the mechanism is unknown, a non-linear model with perceptual feedback accurately simulates the phenomenon. Here we test if a mechanism in the central nervous system underlies thermal TCE. Our model successfully predicted an optimal stimulus, incorporating a transient temperature offset (step-up/step-down), with maximal TCE, resulting in psychophysically verified large decrements in pain response ("offset-analgesia"; mean analgesia: 85%, n = 20 subjects)...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28503674/identifying-brain-nociceptive-information-transmission-in-patients-with-chronic-somatic-pain
#15
Don A Davis, Mariam E Ghantous, Melissa A Farmer, Alexis T Baria, A Vania Apkarian
INTRODUCTION: Recent advances regarding mechanisms of chronic pain emphasize the role of corticolimbic circuitry in predicting risk for chronic pain, independently from site of injury-related parameters. These results compel revisiting the role of peripheral nociceptive signaling in chronic pain. We address this issue by examining what brain circuitry transmit information regarding the intensity of chronic pain and how this information may be related to a common co-morbidity, depression...
October 2016: Pain Reports (Baltimore, Md.)
https://www.readbyqxmd.com/read/28328579/resting-state-functional-connectivity-predicts-longitudinal-pain-symptom-change-in-urologic-chronic-pelvic-pain-syndrome-a-mapp-network-study
#16
Jason J Kutch, Jennifer S Labus, Richard E Harris, Katherine T Martucci, Melissa A Farmer, Sonja Fenske, Connor Fling, Eric Ichesco, Scott Peltier, Bogdan Petre, Wensheng Guo, Xiaoling Hou, Alisa J Stephens, Chris Mullins, Daniel J Clauw, Sean C Mackey, A Vania Apkarian, J Richard Landis, Emeran A Mayer
Chronic pain symptoms often change over time, even in individuals who have had symptoms for years. Studying biological factors that predict trends in symptom change in chronic pain may uncover novel pathophysiological mechanisms and potential therapeutic targets. In this study, we investigated whether brain functional connectivity measures obtained from resting-state functional magnetic resonance imaging at baseline can predict longitudinal symptom change (3, 6, and 12 months after scan) in urologic chronic pelvic pain syndrome...
June 2017: Pain
https://www.readbyqxmd.com/read/28135213/brain-activity-for-tactile-allodynia-a-longitudinal-awake-rat-functional-magnetic-resonance-imaging-study-tracking-emergence-of-neuropathic-pain
#17
Pei-Ching Chang, Maria Virginia Centeno, Daniel Procissi, Alex Baria, A Vania Apkarian
Tactile allodynia, a condition in which innocuous mechanical stimuli are perceived as painful, is a common feature of chronic pain. However, how the brain reorganizes in relation to the emergence of tactile allodynia is still largely unknown. This may stem from the fact that experiments in humans are cross-sectional in nature, whereas animal brain imaging studies typically require anaesthesia rendering the brain incapable of consciously sensing or responding to pain. In this longitudinal functional magnetic resonance imaging study in awake rats, we tracked brain activity with the development of tactile allodynia...
March 2017: Pain
https://www.readbyqxmd.com/read/27852965/a-randomized-placebo-controlled-pilot-study-of-the-efficacy-and-safety-of-d-cycloserine-in-people-with-chronic-back-pain
#18
RANDOMIZED CONTROLLED TRIAL
Thomas J Schnitzer, Souraya Torbey, Kristi Herrmann, Gagan Kaushal, Renita Yeasted, A Vania Apkarian
BACKGROUND: Few effective pharmacological treatment options exist for chronic back pain, the leading cause of disability in the US, and all are associated with significant adverse effects. OBJECTIVE: To determine the efficacy and safety of D-cycloserine, a partial agonist to the N-methyl-D-aspartate receptor, in the treatment of chronic low back pain. METHODS: A total of 41 participants with chronic back pain who met all inclusion and exclusion criteria were enrolled in a double-blind, placebo-controlled randomized pilot trial of D-cycloserine...
2016: Molecular Pain
https://www.readbyqxmd.com/read/27802054/surface-enhanced-femtosecond-stimulated-raman-spectroscopy-at-1-mhz-repetition-rates
#19
Lauren E Buchanan, Natalie L Gruenke, Michael O McAnally, Bogdan Negru, Hannah E Mayhew, Vartkess A Apkarian, George C Schatz, Richard P Van Duyne
Surface-enhanced femtosecond stimulated Raman spectroscopy (SE-FSRS) is an ultrafast Raman technique that combines the sensitivity of surface-enhanced Raman scattering with the temporal resolution of femtosecond stimulated Raman spectroscopy (FSRS). Here, we present the first successful implementation of SE-FSRS using a 1 MHz amplified femtosecond laser system. We compare SE-FSRS and FSRS spectra measured at 1 MHz and 100 kHz using both equal pump average powers and equal pump energies to demonstrate that higher repetition rates allow spectra with higher signal-to-noise ratios to be obtained at lower pulse energies, a significant advance in the implementation of SE-FSRS...
November 17, 2016: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/27788130/brain-connectivity-predicts-placebo-response-across-chronic-pain-clinical-trials
#20
RANDOMIZED CONTROLLED TRIAL
Pascal Tétreault, Ali Mansour, Etienne Vachon-Presseau, Thomas J Schnitzer, A Vania Apkarian, Marwan N Baliki
Placebo response in the clinical trial setting is poorly understood and alleged to be driven by statistical confounds, and its biological underpinnings are questioned. Here we identified and validated that clinical placebo response is predictable from resting-state functional magnetic-resonance-imaging (fMRI) brain connectivity. This also led to discovering a brain region predicting active drug response and demonstrating the adverse effect of active drug interfering with placebo analgesia. Chronic knee osteoarthritis (OA) pain patients (n = 56) underwent pretreatment brain scans in two clinical trials...
October 2016: PLoS Biology
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