scholarly journals Temporal properties of painful contrast enhancement using repetitive stimulation

2021 ◽  
Author(s):  
Tibor M. Szikszay ◽  
Waclaw M. Adamczyk ◽  
Juliette L. M. Levenez ◽  
Philip Gouverneur ◽  
Kerstin Luedtke
Keyword(s):  
Contrast Enhancement ◽  
Electrodermal Activity ◽  
Repetitive Stimulation ◽  
Temporal Contrast ◽  
Temporal Properties ◽  
Heat Stimulus ◽  
Control Paradigm ◽  
Perceived Pain ◽  
Pain Ratings ◽  
Surrogate Measure

Offset analgesia is characterized by a disproportionately large reduction in pain following a small decrease in a heat stimulus and is based on the phenomenon of temporal pain contrast enhancement (TPCE). The aim of this study is to investigate whether this phenomenon can also be induced by repetitive stimulation, i.e., by stimuli that are clearly separated in time. With this aim, the repetitive TPCE paradigm was induced in healthy, pain-free subjects (n=33) at the volar non-dominant forearm using heat stimuli. This paradigm was performed applying three different interstimulus intervals (ISIs): 5, 15, and 25 seconds. All paradigms were contrasted with a control paradigm without temperature change. Participants continuously rated the perceived pain intensity. In addition, electrodermal activity was recorded as a surrogate measure of autonomic arousal. Temporal pain contrast enhancement was confirmed for both ISI 5 seconds (p < 0.001) and ISI 15 seconds (p = 0.005), but not for ISI 25 seconds (p = 0.07), however the magnitude of TPCE did not differ between ISIs (p = 0.11). Electrodermal activity was consistent previous pain ratings, but showing significantly higher autonomic activity being measured. Thus, the phenomenon of temporal contrast enhancement of pain can also be induced by repetitive stimulation. Both the involvement of the autonomic nervous system and the involvement of habituation processes are conceivable, which consequently points to both central and peripheral mechanisms of TPCE.

Transient Analgesia Evoked by Noxious Stimulus Offset

2002 ◽  
Vol 87 (4) ◽  
pp. 2205-2208 ◽  
Author(s):  
Joshua D. Grill ◽  
Robert C. Coghill
Keyword(s):  
Chronic Pain ◽  
Pain Intensity ◽  
Relative Proportion ◽  
Noxious Stimulus ◽  
Temporal Contrast ◽  
Nociceptive Processing ◽  
Perceived Pain ◽  
Pain Ratings ◽  
Stimulus Offset ◽  
Escape Behaviors

Pain has long been thought to wax and wane in relative proportion to fluctuations in the intensity of noxious stimuli. Dynamic aspects of nociceptive processing, however, remain poorly characterized. Here we show that small decreases (±1–3°C) in noxious stimulus temperatures (47–50°C) evoked changes in perceived pain intensity that were as much as 271% greater than those of equal magnitude increases. These decreases in perceived pain intensity were sufficiently large to be indistinguishable from those evoked by 15°C decreases to clearly innocuous levels. Furthermore, decreases in pain ratings following noxious stimulus offset were significantly greater than those occurring during adaptation to constant temperature stimuli. Together, these findings indicate that an analgesic mechanism is activated during noxious stimulus offset. This analgesic phenomenon may serve as a temporal contrast enhancement mechanism to amplify awareness of stimulus offset and to reinforce escape behaviors. Disruption of this mechanism may contribute importantly to chronic pain.

Temporal contrast enhancement and compression of output pulses of ultra-high power lasers

2021 ◽  
Vol 46 (7) ◽  
pp. 1620
Author(s):  
S. Yu. Mironov ◽  
M. V. Starodubtsev ◽  
E. A. Khazanov
Keyword(s):  
Contrast Enhancement ◽  
High Power ◽  
Temporal Contrast ◽  
High Power Lasers

Temporal contrast enhancement of a femtosecond fiber CPA system by filtering of SPM broadened spectra

2018 ◽  
Author(s):  
Joachim Buldt ◽  
Michael Müller ◽  
Robert Klas ◽  
Tino Eidam ◽  
Jens Limpert ◽  
...  
Keyword(s):  
Contrast Enhancement ◽  
Temporal Contrast

Temporal contrast enhancement of ultrashort pulses using a spatiotemporal plasma-lens filter

2020 ◽  
Vol 45 (8) ◽  
pp. 2279
Author(s):  
Ping Zhu ◽  
Arie Zigler ◽  
Xinglong Xie ◽  
Dongjun Zhang ◽  
Qingwei Yang ◽  
...  
Keyword(s):  
Contrast Enhancement ◽  
Ultrashort Pulses ◽  
Temporal Contrast

scholarly journals The effects of flicker adaptation upon temporal contrast enhancement

1983 ◽  
Vol 33 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Frederick L. Kitterle ◽  
Bettina L. Beard
Keyword(s):  
Contrast Enhancement ◽  
Temporal Contrast

scholarly journals Perceived Pain Responses to Foam Rolling Associate with Basal Heart Rate Variability

2021 ◽  
Vol 14 (2) ◽  
pp. 14-21
Author(s):  
Marvette Wilkerson, MS ◽  
Christopher Anderson, BS ◽  
Gregory J. Grosicki, PhD ◽  
Andrew A. Flatt, PhD
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Pain Scale ◽  
Healthy Adults ◽  
Foam Rolling ◽  
Rr Interval ◽  
Natural Logarithm ◽  
Perceived Pain ◽  
Pain Ratings ◽  
Total Body

Background: Foam rolling (FR) is a self-myofascial release technique with unclear effects on autonomic functioning, indexed by heart rate variability (HRV). FR can be perceived as painful or relaxing, which may explain interindividual HRV responses. Purpose: To determine if acute FR alters resting HRV. A secondary aim was to determine if perceived pain during FR would predict HRV responses. Setting: Academic institution. Methods: In a randomized, crossover design, healthy adults (50% female) performed total body FR or control on separate days. Perceived pain ratings were obtained following FR of each muscle group and summed to generate an overall perceived pain rating. Seated measures of the mean RR interval and the natural logarithm of the root-mean square of successive RR interval differences (LnRMSSD, a parasympathetic HRV index) were obtained at 5-10 min pre-, 5-10 min post-, and 25-30 min post-FR. Results: No effects were observed for RR interval (p = .105–.561) or LnRMSSD (p = .110–.129). All effect sizes ranged from trivial–small (0.00–0.26). Changes in RR interval (r = 0.220–0.228, p = .433–.488) and LnRMSSD (r = 0.013–0.256, p = .376–.964) were not associated with pain scale sum. Baseline LnRMSSD was associated with pain scale sum (r = -0.663; p = .001). Conclusion: FR did not systematically alter HRV, nor did perceived pain ratings predict HRV responses. Those with lower pre-FR HRV reported higher perceived pain during FR. Basal cardiac autonomic activity may, therefore, influence pain sensitivity to FR in healthy adults.

Temporal Contrast Enhancement via GABAC Feedback at Bipolar Terminals in the Tiger Salamander Retina

1998 ◽  
Vol 79 (4) ◽  
pp. 2171-2180 ◽  
Author(s):  
Cun-Jian Dong ◽  
Frank S. Werblin
Keyword(s):  
Receptor Antagonist ◽  
Contrast Enhancement ◽  
Ganglion Cells ◽  
Lucifer Yellow ◽  
Light Stimulus ◽  
Ringer Solution ◽  
Bipolar Cells ◽  
Voltage Response ◽  
Tiger Salamander ◽  
Temporal Contrast

Dong, Cun-Jian and Frank S. Werblin. Temporal contrast enhancement via GABAC feedback at bipolar terminals in the tiger salamander retina. J. Neurophysiol. 79: 2171–2180, 1998. Most retinal amacrine (ACs) and ganglion cells (GCs) express temporal contrast by generating action potentials at only the onset and offset of the light stimulus. This study investigated the neural mechanisms that underlie this temporal contrast enhancement. Whole cell patch recordings were made from bipolar cells (BCs), ACs, and GCs in the retinal slice preparation. The cells were identified by the locations of their somas in the inner nuclear layer and ganglion cell layers, their characteristic light responses, and morphology revealed by Lucifer yellow staining. Depolarizing a single BC with a brief voltage pulse elicited a Cl− tail current that was completely abolished when Ca2+ entry to bipolar terminals was prevented, by either removing Ca2+ from the Ringer solution or blocking Ca2+ channels with Co2+. This suggests that the Cl− current is Ca2+-dependent. In those bipolar cells whose axon terminals were cutoff during slicing no Cl− current was observed, indicating that this current is generated at the synaptic terminals. The Cl− current consists of a predominant synaptic component that can be blocked by the non- N-methyl-d-aspartate (NMDA) glutamate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or by the γ-aminobutyric acid-C (GABAC) receptor antagonist picrotoxin. There also exists a relatively small nonsynaptic component. Thus both glutamatergic and GABAergic transmission were involved in the generation of this Cl− current, suggesting that it is mediated by a recurrent feedback to bipolar cells. Picrotoxin, which blocks both GABAC receptors at BC terminals and GABAA receptors on the dendrites of ACs and GCs, converted the light-elicited voltage response in most on-off ACs and GCs from transient to sustained. Bicuculline, which blocks only the GABAA receptors, did not prolong the transient response in on-off ACs and GCs. This suggests that a negative feedback mediated by the GABAC receptor on the bipolar terminals is responsible for making these responses transient. After the GABAergic feedback was blocked with picrotoxin the light-elicited voltage responses (recorded under current clamp) were more sustained than the current responses (recorded under voltage clamp) to the same light stimuli. This suggests that a voltage-dependent conductance converts the relatively transient current responses to more sustained voltage responses. Our results imply a synaptically driven local GABAergic feedback at bipolar terminals, mediated by GABAC receptors. This feedback appears to be a significant component of the mechanism underlying temporal contrast enhancement in on-off ACs and GCs.

scholarly journals Stepwise increasing sequential offsets cannot be used to deliver high thermal intensities with little or no perception of pain

2019 ◽  
Vol 122 (2) ◽  
pp. 729-736
Author(s):  
Stuart W. G. Derbyshire ◽  
Victoria Jane En Long ◽  
Christopher L. Asplund
Keyword(s):  
Low Temperature ◽  
Stimulus Intensity ◽  
Pain Perception ◽  
Noxious Heat ◽  
Pain Experience ◽  
Analgesic Effects ◽  
Heat Stimulus ◽  
Long Duration ◽  
Pain Ratings ◽  
Noxious Stimuli

Offset analgesia (OA) is the disproportionate decrease in pain experience following a slight decrease in noxious heat stimulus intensity. We tested whether sequential offsets would allow noxious temperatures to be reached with little or no perception of pain. Forty-eight participants continuously rated their pain experience during trials containing trains of heat stimuli delivered by Peltier thermode. Stimuli were adjusted through either stepwise sequential increases of 2°C and decreases of 1°C or direct step increases of 1°C up to a maximum of 46°C. Step durations (1, 2, 3, or 6 s) varied by trial. Pain ratings generally followed presented temperature, regardless of step condition or duration. For 6-s steps, OA was observed after each decrease, but the overall pain trajectory was unchanged. We found no evidence that sequential offsets could allow for little pain perception during noxious temperature presentation. NEW & NOTEWORTHY Offset analgesia is the disproportionate decrease in pain experience following a slight decrease in noxious heat stimulus intensity. We tested whether sequential offsets would allow noxious temperatures to be reached with little or no perception of pain. We found little evidence of such overall analgesia. In contrast, we observed analgesic effects after each offset with long-duration stimuli, even with relatively low-temperature noxious stimuli.

scholarly journals No temporal contrast enhancement of simple decreases in noxious heat

2019 ◽  
Vol 121 (5) ◽  
pp. 1778-1786 ◽  
Author(s):  
Brianna Beck ◽  
Sahana Gnanasampanthan ◽  
Gian Domenico Iannetti ◽  
Patrick Haggard
Keyword(s):  
Contrast Enhancement ◽  
Initial Temperature ◽  
Forced Choice ◽  
Choice Task ◽  
Temporal Contrast ◽  
Contact Heat ◽  
Noxious Heat ◽  
Contrast Mechanism ◽  
Forced Choice Task ◽  
Better Than

Offset analgesia (OA) studies have found that small decreases in the intensity of a tonic noxious heat stimulus yield a disproportionately large amount of pain relief. In the classic OA paradigm, the decrease in stimulus intensity is preceded by an increase of equal size from an initial noxious level. Although the majority of researchers believe this temporal sequence of two changes is important for eliciting OA, it has also been suggested that the temporal contrast mechanism underlying OA may enhance detection of simple, isolated decreases in noxious heat. To test whether decreases in noxious heat intensity, by themselves, are perceived better than increases of comparable sizes, we used an adaptive two-interval alternative forced choice task to find perceptual thresholds for increases and decreases in radiant and contact heat. Decreases in noxious heat were more difficult to perceive than increases of comparable sizes from the same initial temperature of 45°C. In contrast, decreases and increases were perceived equally well within a common range of noxious temperatures (i.e., when increases started from 45°C and decreases started from 47°C). In another task, participants rated the pain intensity of heat stimuli that randomly and unpredictably increased, decreased, or remained constant. Ratings of unpredictable stimulus decreases also showed no evidence of perceptual enhancement. Our results demonstrate that there is no temporal contrast enhancement of simple, isolated decreases in noxious heat intensity. Combined with previous OA findings, they suggest that long-lasting noxious stimuli that follow an increase-decrease pattern may be important for eliciting the OA effect. NEW & NOTEWORTHY Previous research suggested that a small decrease in noxious heat intensity feels surprisingly large because of sensory enhancement of noxious stimulus offsets (a simplified form of “offset analgesia”). Using a two-alternative forced choice task where participants detected simple increases or decreases in noxious heat, we showed that decreases in noxious heat, by themselves, are no better perceived than increases of comparable sizes. This suggests that a decrease alone is not sufficient to elicit offset analgesia.

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