References of "Anton, Fernand 50000430"
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See detailPeripheral and central alterations affecting spinal nociceptive processing and pain at adulthood in rats exposed to neonatal maternal deprivation
Juif, Pierre-Eric; Salio, Chiara; Zell, Vivien UL et al

in European Journal of Neuroscience (2016)

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See detailInter-individual differences in cardiovascular reactivity and the perception of the thermal grill illusion of pain
Scheuren, Raymonde UL; Duschek, Stefan; Schulz, André UL et al

Speeches/Talks (2015)

Background: Evidence has been given that there exists a functional relationship between the cardiovascular and the pain regulatory system. Alterations in blood pressure and concomitant changes in ... [more ▼]

Background: Evidence has been given that there exists a functional relationship between the cardiovascular and the pain regulatory system. Alterations in blood pressure and concomitant changes in baroreceptor activation contribute to the modulation of pain sensitivity It could be shown that blood pressure, baroreflex sensitivity, and cardiac vagal tone (indexed by heart rate variability, HRV) are inversely associated to pain sensitivity. We aimed assessing the same cardiovascular parameters in a thermal grill paradigm to test the assumption of a relationship between inter-individual differences in autonomic cardiac control and the perception of the thermal grill illusion of pain (TGI). Methods: All participants (N = 52) were stimulated three times during one minute with the temperatures of 15°C and 41°C set at the interlaced cold and warm bars of the water-bath driven thermal grill. Blood pressure and heart rate were recorded concomitantly. Numerical rating scales (NRS; 0–100) were used to quantify subjective paradoxical pain intensity and pain unpleasantness perceptions. Results: A positive association between cardiac vagal tone and paradoxical pain sensitivity could be revealed. Higher resting HRV, as expressed by higher respiratory sinus arrhythmia (RSA), made it overall more likely to perceive the TGI. In contrast, blood pressure and the susceptibility to the TGI were inversely related. Volunteers displaying higher spontaneous blood pressure values in the first thermal grill stimulation phase did not feel the illusive pain as compared to those who presented significantly lower sympathetic arousal and perceived the TGI. Conclusion: The present physiological findings complement previous evidence of an impact of psychological characteristics on the individual disposition to paradoxical pain perceptions. [less ▲]

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See detailRelationship between cardiovascular reactivity and the perception of the thermal grill illusion of pain
Scheuren, Raymonde UL; Duschek, Stefan; Schulz, André UL et al

Poster (2015, September 03)

Alterations in blood pressure (BP) and concomitant changes in baroreceptor activation contribute to the modulation of pain sensitivity to warrant homeostatic regulation processes [1][2]. Numerous pain ... [more ▼]

Alterations in blood pressure (BP) and concomitant changes in baroreceptor activation contribute to the modulation of pain sensitivity to warrant homeostatic regulation processes [1][2]. Numerous pain studies have described an inverse relationship between BP and nociceptive sensitivity [3][4][5]. It is not known whether a similar relationship plays a role in the framework of the induction of pain in the absence of noxious stimulation. The thermal grill (TG) paradigm is commonly used to trigger this type of paradoxical pain also termed thermal grill illusion of pain (TGI). The goal of the present study was to explore the relationship between cardiovascular activity/reactivity and paradoxical pain sensitivity to get additional insight in the variability of responsiveness (responders and non-responders) to TG stimulation described in the literature [6][7]. We hypothesized that higher BP would be associated with stronger pain inhibitory effects in participants not perceiving the thermal grill illusion of pain (TGI). We moreover expected that the perception of paradoxical pain in the responder group would be paired with lower BP. We tested this hypothesis by comparing both groups with respect to their spontaneous cardiovascular activity (recorded in resting conditions) and their cardiovascular responses to TG stimulation. [less ▲]

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See detailSuffering as an independent component of the experience of pain
Bustan, Smadar UL; Gonzalez-Roldan, Ana; Kamping, Sandra et al

in European Journal of Pain (2015)

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See detailCorticosterone analgesia is mediated by the spinal production of neuroactive metabolites that enhance GABAergic inhibitory transmission on dorsal horn rat neurons.
Zell, Vivien; Juif, Pierre-Eric; Hanesch, Ulrike UL et al

in The European journal of neuroscience (2015)

Corticosterone (CORT) is a glucocorticoid produced by adrenal glands under the control of the hypothalamic-pituitary-adrenal axis. Circulating CORT can enter the central nervous system and be reduced to ... [more ▼]

Corticosterone (CORT) is a glucocorticoid produced by adrenal glands under the control of the hypothalamic-pituitary-adrenal axis. Circulating CORT can enter the central nervous system and be reduced to neuroactive 3alpha5alpha-reduced steroids, which modulate GABAA receptors. In the dorsal spinal cord, GABAergic transmission modulates integration of nociceptive information. It has been shown that enhancing spinal inhibitory transmission alleviates hyperalgesia and allodynia. Therefore, the spinal neuronal network is a pivotal target to counteract pain symptoms. Thus, any increase in spinal 3alpha5alpha-reduced steroid production enhancing GABAergic inhibition should reduce nociceptive message integration and the pain response. Previously, it has been shown that high levels of plasma glucocorticoids give rise to analgesia. However, to our knowledge, nothing has been reported regarding direct non-genomic modulation of neuronal spinal activity by peripheral CORT. In the present study, we used combined in vivo and in vitro electrophysiology approaches, associated with measurement of nociceptive mechanical sensitivity and plasma CORT level measurement, to assess the impact of circulating CORT on rat nociception. We showed that CORT plasma level elevation produced analgesia via a reduction in C-fiber-mediated spinal responses. In the spine, CORT is reduced to the neuroactive metabolite allotetrahydrodeoxycorticosterone, which specifically enhances lamina II GABAergic synaptic transmission. The main consequence is a reduction in lamina II network excitability, reflecting a selective decrease in the processing of nociceptive inputs. The depressed neuronal activity at the spinal level then, in turn, leads to weaker nociceptive message transmission to supraspinal structures and hence to alleviation of pain. [less ▲]

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See detailLernskript Psychologie: Kapitel 4: Biopsychologie
Schmithüsen, Franziska; Anton, Fernand UL

in Schmithüsen, Franziska (Ed.) Lernskript Psychologie (2014)

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See detailExperimental induction of suffering: why suffering is not the same as unpleasantness
Brunner, Michael; Löffler, Martin; Kamping, Sandra et al

Scientific Conference (2014, October 10)

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See detail<the impact of self and controllability on diferent pain dimensions
Löffler, Martin; Brunner, Michael; Flor, Herta et al

Scientific Conference (2014, October 10)

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See detailIntroducing the dimension of suffering to mechanically induced phasic and tonic pain
González Roldán, Ana Maria UL; Bustan, Smadar UL; Kamping, Sandra et al

Scientific Conference (2014, October 10)

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See detailVagally mediated heart rate variability is a predictor for the occurrence of the thermal grill-induced pain illusion
Scheuren, Raymonde UL; Sütterlin, Stefan UL; Anton, Fernand UL

Poster (2014, October)

Aim: Unpleasantness and negative affect accompany the sensory experience of pain. Both components of pain are heavily influenced by cognitive and emotional processes. In this framework, alterations in ... [more ▼]

Aim: Unpleasantness and negative affect accompany the sensory experience of pain. Both components of pain are heavily influenced by cognitive and emotional processes. In this framework, alterations in baroreceptor reactivity and concomitant changes in cardiac rhythm and blood pressure related to these processes contribute to the modulation of pain sensitivity. Furthermore, self-regulatory capacity has been shown to play a major role in the regulation of cognitive, affective, and behavioural reactions to adverse contexts. These regulatory mechanisms include adjustment of cardiovascular activity and heavily depend on prefrontal cortical processing. Vagally mediated heart rate variability (HRV) at rest is an indicator of the prefrontally modulated vagal activation and has been used as a psychophysiological marker for self-regulatory capacity. The present study investigated the predictive value of the trait self-regulation in the triggering of the thermal grill-induced pain illusion (TGI). We hypothesized inter-individual differences in paradoxical pain perception to be predicted by self-regulatory capacity in a way that participants displaying lower levels of self-regulation should be more likely to perceive the painful grill illusion than subjects with relatively higher self-regulation ability. Methods: A total of 54 healthy participants were recruited among university students and staff. A custom-built, water-bath driven thermal grill device, with interlaced cold and warm glass tubes, was used for the induction of the TGI. A pre-set temperature combination of 15°C and 41°C was applied to the palm of the dominant hand with stimulus durations of 1 min. Subsequent control conditions consisted in the interlaced combination of a baseline temperature of 32°C with one of the stimulus temperatures mentioned above. The procedure was repeated three times. The volunteers used numerical rating scales ranging from 0-100 to rate sensory and affective pain perceptions in intervals of 15 seconds. Vagally mediated HRV at rest was assessed prior to the thermal stimulation protocols. Results: Time-domain components of HRV used as graded indicators of parasympathetic activity and of the extent of self-regulation significantly predicted the possibility of an occurrence of pain and unpleasantness sensations in response to thermal grill stimulation (p <.05). Participants characterized in this way were more likely to express paradoxical pain than subjects not displaying similar levels of HRV. Conclusion: The present results support previous findings indicating an impact of several psychological traits on the individual disposition to paradoxical pain perceptions. Self-regulation ability, operationalized as vagally mediated heart rate variability, can partially explain the probability of perceived pain in response to non-noxious thermal grill stimulation. [less ▲]

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See detailRumination and interoceptive accuracy predict the occurrence of the thermal grill illusion of pain
Scheuren, Raymonde UL; Sütterlin, Stefan UL; Anton, Fernand UL

in BMC Psychology (2014), 2(22),

Background: While the physiological mechanisms of the thermal grill illusion of pain (TGI) are largely understood, psychological determinants remain mainly unknown. The present study aimed to investigate ... [more ▼]

Background: While the physiological mechanisms of the thermal grill illusion of pain (TGI) are largely understood, psychological determinants remain mainly unknown. The present study aimed to investigate whether cognitive and affective personality traits encompassing rumination, interoception and suggestibility contribute to the inducibility of paradoxical pain. Methods: The dominant hand of 54 healthy volunteers was stimulated with a water-bath driven thermal grill providing an interlaced temperature combination of 15 and 41°C. Pain intensity and pain unpleasantness perceptions were rated on a numerical scale (NRS). Traits were assessed via questionnaires, the heartbeat-tracking task, and warmth suggestions. Results: Logistic regression analyses uncovered trait rumination and interoceptive accuracy (IA) as major predictors of the likelihood of the illusive pain occurrence (all p < .05). Rumination and suggestibility had an impact on unpleasant pain perceptions. Conclusion: Our findings demonstrate a significant influence of psychological aspects on the individual disposition to the painful grill illusion (PGI). [less ▲]

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See detailNeonatal maternal separation stress alters neuropathic pain behaviour and spinal nociceptive processing in rats
Genty, Julien UL; Le Coz, Glenn-Marie UL; Anton, Fernand UL et al

Scientific Conference (2014)

Aims Early life stress enhances vulnerability to metabolic and mental disorders in adulthood. Altered pain sensitivity and dysfunctional emotional processing have been described in this context. We ... [more ▼]

Aims Early life stress enhances vulnerability to metabolic and mental disorders in adulthood. Altered pain sensitivity and dysfunctional emotional processing have been described in this context. We assessed the impact of neonatal maternal separation (MS) on chronic constriction injury (CCI) induced neuropathic pain behavior and biochemical spinal processing in early adulthood. Methods Four groups of rats were tested: Controls, MS, CCI, MS+CCI. For MS, pups were separated from the dam from postnatal day 2 to 12 for 3 hours per day. At an age of 7 weeks mechanical and thermal pain thresholds where assessed by the von Frey and the cold plate test. CCI surgery was performed in two of the experimental groups and behavioural measurements were continued until day 21 post surgery. After decapitation spinal cord levels L4/L5 were removed and total RNA was extracted to perform qPCR. Results MS alone did not affect pain thresholds. Surprisingly, MS+CCI rats were less sensitive to mechanical and thermal stimuli compared to CCI. Regarding the biochemical data, MS as well as MS+CCI led to an upregulation of glial markers, cytokines and growth factors and to a downregulation of glutamate receptors and transporters. Conclusion Behavioral and biochemical data are conflicting. The reduced pain sensitivity in MS animals is in contrast to activation of glia and enhanced expression of cytokines but in line with reduced glutamatergic signalling. Since MS and MS+CCI groups did not differ, pain-related processing may have been outweighed by stress-related programming of biochemical reactivity. [less ▲]

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See detailGlucocorticoid-Mediated Enhancement of Glutamatergic Transmission May Outweigh Anti-Inflammatory Effects under Conditions of Neuropathic Pain.
Le Coz, Glenn-Marie UL; Anton, Fernand UL; Hanesch, Ulrike UL

in PloS one (2014), 9(3), 91393

At the clinical level comorbidity between chronic pain and dysfunctional hypothalamus-pituitary-adrenal (HPA) axis is well established. We aimed to identify causal relationships in a model of neuropathic ... [more ▼]

At the clinical level comorbidity between chronic pain and dysfunctional hypothalamus-pituitary-adrenal (HPA) axis is well established. We aimed to identify causal relationships in a model of neuropathic pain (chronic constriction injury, CCI) by studying the effects of glucocorticoid receptor agonist (dexamethasone) and antagonist (RU-486) administration on pain behavior and spinal biochemical mediators. Daily injections were performed in Sprague Dawley rats. Weight, plasma corticosterone levels and mechanical pain thresholds were assessed before and during 21 days post-CCI. At days four and 21 we investigated the mRNA expression of spinal mediators. In the dexamethasone-injected group, we observed a diminution of body weight and plasma corticosterone levels during the 21 days post surgery period and a more pronounced pain sensitivity until day 7 post-CCI. This enhanced pain sensitivity in the early period following nerve injury was accompanied by a transient increase of the glutamate receptors mGluR5 and NMDA at day 4. However, at this time point we did not observe any effect of the agonist/antagonist injections on the mRNA expression of pro-inflammatory cytokines. The RU-486-injected rats showed a slight mechanical hypoalgesia until 7 days post-CCI, but without any significant correlation with the expression of the measured markers. Our results indicate that glucocorticoid-related modulations of neuropathic pain processing may rather depend on a modification of glutamatergic transmission than on a change in pro-inflammatory cytokine expression. [less ▲]

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See detailDifferential neuropathic pain sensitivity and expression of spinal mediators in Lewis and Fischer 344 rats.
Le Coz, Glenn-Marie UL; Fiatte, Cathy; Anton, Fernand UL et al

in BMC neuroscience (2014), 15(1), 35

BACKGROUND: Altered hypothalamo-pituitary-adrenal (HPA) axis activity may be accompanied by a modulation of pain sensitivity. In a model of neuropathic pain (chronic constriction injury, CCI) we ... [more ▼]

BACKGROUND: Altered hypothalamo-pituitary-adrenal (HPA) axis activity may be accompanied by a modulation of pain sensitivity. In a model of neuropathic pain (chronic constriction injury, CCI) we investigated the onset and maintenance of mechanical allodynia/hyperalgesia and the expression of biochemical mediators potentially involved in spinal cell modulation in two rat strains displaying either hypo- (Lewis-LEW) or hyper- (Fischer 344-FIS) reactivity of the HPA axis. RESULTS: Mechanical pain thresholds and plasmatic corticosterone levels were assessed before and during periods of 4 or 21 days following CCI surgery. At the end of the respective protocols, the mRNA expression of glial cell markers (GFAP and Iba1) and glutamate transporters (EAAT3 and EAAT2) were examined. We observed a correlation between the HPA axis reactivity and the pain behavior but not as commonly described in the literature; LEW rats seemed to be less sensitive than FIS from 4 to 14 days after the CCI surgery when looking at the mechanical allodynia/hyperalgesia. However, the biochemical spinal markers expression we observed is conflicting. CONCLUSION: We did not find a specific causal relation between the pain behavior and the glial cell activation or the expression of the glutamate transporters, suggesting that the interaction between the HPA axis and the spinal activation pattern is more complex in a context of neuropathic pain. [less ▲]

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See detailPlasma glucocorticoids differentially modulate phasic and tonic GABA inhibition during early postnatal development in rat spinal lamina II.
Zell, Vivien; Hanesch, Ulrike UL; Poisbeau, Pierrick et al

in Neuroscience letters (2014), 578

Nociceptive processing is tuned by GABAA receptor-mediated inhibition in the spinal cord dorsal horn that undergoes postnatal maturation in rodents. These GABAergic inhibitory postsynaptic currents (IPSCs ... [more ▼]

Nociceptive processing is tuned by GABAA receptor-mediated inhibition in the spinal cord dorsal horn that undergoes postnatal maturation in rodents. These GABAergic inhibitory postsynaptic currents (IPSCs) are modulated by 3alpha5alpha-reduced steroids during early postnatal development in spinal cord lamina II. Thus an enhanced phasic inhibition is present in neonates and decreases over time. GABA can also activate extrasynaptic receptors, giving rise to tonic inhibition. In this study, we characterized the contribution of plasma corticosterone (CORT) to postnatal maturation of spinal phasic and, for the first time, tonic GABAergic inhibitions. We used Fisher and Lewis rat strains displaying respectively high and low hypothalamic-pituitary-adrenal axis reactivity, compared to control Sprague-Dawley rats. Measured plasma CORT levels were significantly higher in Fisher rats, which also displayed significantly higher mechanical nociceptive thresholds, supporting the hypothesis of an antinociceptive action of CORT. Recorded GABAA IPSCs shortened during maturation in all strains while remaining larger in Fisher rats. Blocking the 5alpha-reduction of steroids in Fisher rats produced a further decrease of IPSC deactivation time constant. In contrast, GABAA tonic inhibition progressively increased during maturation, without any difference among strains. In conclusion, we show that both phasic and tonic GABAergic inhibitions undergo postnatal maturation in lamina II. Moreover spinal production of 3alpha5alpha-reduced steroids that presumably derive from plasma CORT is correlated to spinal GABAA phasic (but not tonic) inhibition and to mechanical nociceptive thresholds. [less ▲]

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See detailBeep Tones Attenuate Pain following Pavlovian Conditioning of an Endogenous Pain Control Mechanism
Scheuren, Raymonde UL; Anton, Fernand UL; Erpelding, Nathalie et al

in PLoS ONE (2014), 9(2), 88710

Heterotopic noxious counter-stimulation (HNCS) is commonly used to study endogenous pain control systems. The resulting pain inhibition is primarily based on spinal cord-brainstem loops. Recently ... [more ▼]

Heterotopic noxious counter-stimulation (HNCS) is commonly used to study endogenous pain control systems. The resulting pain inhibition is primarily based on spinal cord-brainstem loops. Recently, functional imaging studies have shown that limbic structures like the anterior cingulate cortex and amygdala are also implicated. Since these structures are involved in learning processes, it is possible that the HNCS-induced pain inhibition may depend on specific cues from the environment that have been associated with pain reduction through associative learning. We investigated the influence of Pavlovian conditioning on HNCS-induced pain inhibition in 32 healthy subjects by using a differential conditioning paradigm in which two different acoustic stimuli were either repeatedly paired or unpaired with HNCS. Series of noxious electrical pulse trains delivered to the non-dominant foot served as test stimuli. Diffuse noxious inhibitory control (DNIC)-like effects were induced by concurrent application of tonic HNCS (immersion of the contralateral hand in ice water). Subjective pain intensity and pain unpleasantness ratings and electromyographic recordings of the facial corrugator muscle and the nocifensive RIII flexion reflex were used to measure changes in pain sensitivity. HNCS induced significant pain and reflex inhibitions. In the post-conditioning phase, only the paired auditory cue was able to significantly reduce pain perceptions and corrugator muscle activity. No conditioned effect could be observed in RIII reflex responses. Our results indicate that the functional state of endogenous pain control systems may depend on associative learning processes that, like in the present study, may lead to an attenuation of pain perception. Similar albeit opposite conditioning of pain control mechanisms may significantly be involved in the exacerbation and chronification of pain states. [less ▲]

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See detailRumination, interoceptive awareness and suggestibility predict the occurrence of the thermal grill illusion
Scheuren, Raymonde UL; Sütterlin, Stefan UL; Anton, Fernand UL

Poster (2013, October 10)

ruminationInterposed non-noxious cold and warm cutaneous stimuli applied via a thermal grill have repeatedly been shown to generate a paradoxical pain sensation, also described as ‘thermal grill illusion ... [more ▼]

ruminationInterposed non-noxious cold and warm cutaneous stimuli applied via a thermal grill have repeatedly been shown to generate a paradoxical pain sensation, also described as ‘thermal grill illusion of pain’. According to the ‘central disinhibition theory’ proposed by Craig and Bushnell [1], the pain phenomenon commonly qualified as burning can be explained by “an unmasking of cold-evoked activity of polymodal nociceptive lamina I spinothalamic neurons (activation by polymodal Cnociceptors) resulting from the reduction of normal coldevoked activity of thermoreceptive lamina I spinothalamic neurons (activation by Aδ cooling thermoreceptors) by spatial summation of the simultaneous warm stimuli in the thermoreceptive but not the nociceptive neurons.” Since a significant part of the tested subjects do however not display the thermal grill percept, it may be hypothesized that not only physiological-, but also psychological determinants play a crucial role in the generation of the paradoxical pain. Sad mood [2] and anxiety [3] have already been proposed as relevant psychological factors. The aim of the present research consisted in validating our custom made, water-driven and fMRI compatible thermal grill device [4], in identifying thermal grill ‘responders’ and ‘non-responders’ and in investigating whether different personality traits or states constitute predictors for the elicitation of the thermal grill illusion. [less ▲]

Detailed reference viewed: 100 (7 UL)