scholarly journals Brain activity and connectivity attributable to nociceptive signal block

2016 ◽  
Author(s):  
Michael L Meier ◽  
Sonja Widmayer ◽  
Nuno M.P. de Matos ◽  
Jetmir Abazi ◽  
Dominik A Ettlin

AbstractConverging lines of evidence indicate that the pain experience emerges from distributed cortical nodes that share nociceptive information. While the theory of a single pain center is still not falsifiable by current neuroimaging technology, the validation of distinct brain mechanisms for acute pain and its relief is ongoing and strongly dependent on the employed experimental design. In the current study including a total of 28 subjects, a recently presented, innovative experimental approach was adopted that is able to clearly differentiate painful from non-pain perceptions without changing stimulus strength and while recording brain activity using functional magnetic resonance imaging (fMRI). Namely, we applied a repetitive and purely nociceptive stimulus to the tooth pulp with subsequent suppression of the nociceptive barrage via a regional nerve block. The study aims were 1) to replicate previous findings of acute pain demonstrating a fundamental role of the operculo-insular region and 2) to explore its functional connectivity during pain and subsequent relief. The brain activity reduction in the posterior insula (pINS) due to pain extinction was confirmed. In addition, the posterior S2 region (OP1) showed a similar activity pattern, thus confirming the relevance of the operculo-insular cortex in acute pain processing. Furthermore, the functional connectivity analysis yielded an enhanced positive coupling of the pINS with the cerebellar culmen during pain relief, whereas the OP1 demonstrated a positive coupling with the posterior midcingulate cortex during pain. The current results support the conceptual synthesis of localized specialization of pain processing with interactions across distributed neural targets.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Davide Sometti ◽  
Chiara Ballan ◽  
Huiying Wang ◽  
Christoph Braun ◽  
Paul Enck

AbstractIt is well-known that antibiotics affect commensal gut bacteria; however, only recently evidence accumulated that gut microbiota (GM) can influence the central nervous system functions. Preclinical animal studies have repeatedly highlighted the effects of antibiotics on brain activity; however, translational studies in humans are still missing. Here, we present a randomized, double-blind, placebo-controlled study investigating the effects of 7 days intake of Rifaximin (non-absorbable antibiotic) on functional brain connectivity (fc) using magnetoencephalography. Sixteen healthy volunteers were tested before and after the treatment, during resting state (rs), and during a social stressor paradigm (Cyberball game—CBG), designed to elicit feelings of exclusion. Results confirm the hypothesis of an involvement of the insular cortex as a common node of different functional networks, thus suggesting its potential role as a central mediator of cortical fc alterations, following modifications of GM. Also, the Rifaximin group displayed lower connectivity in slow and fast beta bands (15 and 25 Hz) during rest, and higher connectivity in theta (7 Hz) during the inclusion condition of the CBG, compared with controls. Altogether these results indicate a modulation of Rifaximin on frequency-specific functional connectivity that could involve cognitive flexibility and memory processing.


2021 ◽  
Author(s):  
Lina Koppel ◽  
Giovanni Novembre ◽  
Robin Kämpe ◽  
Mattias Savallampi ◽  
India Morrison

AbstractPredicting that a stimulus is painful facilitates action to avoid harm. But does the prediction of upcoming painful events engage the same or different processes than acting to avoid or reduce current pain? In this fMRI experiment, we investigated brain activity as a function of current and predicted painful or nonpainful thermal stimulation, and the ability of voluntary action to affect the duration of the upcoming stimulation. Participants (n = 30) performed a task which involved the administration of a painful or nonpainful stimulus (S1), which predicted an immediately subsequent very painful or nonpainful stimulus (S2). Participants’ task was to press a response button within a short time window upon the presentation of a response cue during S1. On action-effective trials, pressing the button within the specified time window reduced the duration of the upcoming stimulation. On action-ineffective trials, pressing the button had no effect on upcoming stimulation. Predicted pain increased activation in regions including anterior cingulate cortex (ACC), midcingulate cortex (MCC), and insula; however, activation in ACC and MCC depended on whether a meaningful action was performed, with MCC activation showing a direct relationship with motor output. Region-of-interest analyses revealed that insula’s responses for predicted pain were also modulated by potential action consequences, especially in the left hemisphere, albeit without a direct relationship with motor output. Taken together, these findings suggest that cortical pain processing is not specifically tied to the sensory stimulus, but instead depends on the consequences of that stimulus for sensorimotor control of behavior.Significance statementDuring acute pain, the processing of an acute sensory event likely occurs in parallel with predictive processing about its relevance for current and upcoming voluntary behavior. Here, we temporally separated the functional processes underlying current and predicted pain and found that activation in regions typically implicated in acute pain is modulated both by the noxious nature of upcoming events, as well as by the possibility to affect those events via voluntary action. Specifically, activation in anterior cingulate cortex (ACC), midcingulate cortex (MCC), and insula during the delivery of a painful or nonpainful stimulus was modulated by whether an upcoming stimulus would be painful. Furthermore, ACC/MCC involvement in pain prediction depended on whether a meaningful action was performed, i.e., whether a button-press action would reduce the duration of the upcoming stimulus. Although insula activation was also affected by the possibility of the button-press action to reduce the duration of the upcoming stimulation, only MCC had a direct relationship with motor output.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuang Zhang ◽  
Gui-Ping Gao ◽  
Wen-Qing Shi ◽  
Biao Li ◽  
Qi Lin ◽  
...  

Abstract Background Previous studies have demonstrated that strabismus amblyopia can result in markedly brain function alterations. However, the differences in spontaneous brain activities of strabismus amblyopia (SA) patients still remain unclear. Therefore, the current study intended to employthe voxel-mirrored homotopic connectivity (VMHC) method to investigate the intrinsic brain activity changes in SA patients. Purpose To investigate the changes in cerebral hemispheric functional connections in patients with SA and their relationship with clinical manifestations using the VMHC method. Material and methods In the present study, a total of 17 patients with SA (eight males and nine females) and 17 age- and weight-matched healthy control (HC) groups were enrolled. Based on the VMHC method, all subjects were examined by functional magnetic resonance imaging. The functional interaction between cerebral hemispheres was directly evaluated. The Pearson’s correlation test was used to analyze the clinical features of patients with SA. In addition, their mean VMHC signal values and the receiver operating characteristic curve were used to distinguish patients with SA and HC groups. Results Compared with HC group, patients with SA had higher VMHC values in bilateral cingulum ant, caudate, hippocampus, and cerebellum crus 1. Moreover, the VMHC values of some regions were positively correlated with some clinical manifestations. In addition, receiver operating characteristic curves presented higher diagnostic value in these areas. Conclusion SA subjects showed abnormal brain interhemispheric functional connectivity in visual pathways, which might give some instructive information for understanding the neurological mechanisms of SA patients.


2018 ◽  
Vol 29 (5) ◽  
pp. 1984-1996 ◽  
Author(s):  
Dardo Tomasi ◽  
Nora D Volkow

Abstract The origin of the “resting-state” brain activity recorded with functional magnetic resonance imaging (fMRI) is still uncertain. Here we provide evidence for the neurovascular origins of the amplitude of the low-frequency fluctuations (ALFF) and the local functional connectivity density (lFCD) by comparing them with task-induced blood-oxygen level dependent (BOLD) responses, which are considered a proxy for neuronal activation. Using fMRI data for 2 different tasks (Relational and Social) collected by the Human Connectome Project in 426 healthy adults, we show that ALFF and lFCD have linear associations with the BOLD response. This association was significantly attenuated by a novel task signal regression (TSR) procedure, indicating that task performance enhances lFCD and ALFF in activated regions. We also show that lFCD predicts BOLD activation patterns, as was recently shown for other functional connectivity metrics, which corroborates that resting functional connectivity architecture impacts brain activation responses. Thus, our findings indicate a common source for BOLD responses, ALFF and lFCD, which is consistent with the neurovascular origin of local hemodynamic synchrony presumably reflecting coordinated fluctuations in neuronal activity. This study also supports the development of task-evoked functional connectivity density mapping.


2017 ◽  
Vol 30 (2) ◽  
pp. 571-579 ◽  
Author(s):  
Amy Krain Roy ◽  
Randi Bennett ◽  
Jonathan Posner ◽  
Leslie Hulvershorn ◽  
F. Xavier Castellanos ◽  
...  

AbstractSevere temper outbursts (STO) in children are associated with impaired school and family functioning and may contribute to negative outcomes. These outbursts can be conceptualized as excessive frustration responses reflecting reduced emotion regulation capacity. The anterior cingulate cortex (ACC) has been implicated in negative affect as well as emotional control, and exhibits disrupted function in children with elevated irritability and outbursts. This study examined the intrinsic functional connectivity (iFC) of a region of the ACC, the anterior midcingulate cortex (aMCC), in 5- to 9-year-old children with STO (n = 20), comparing them to children with attention-deficit/hyperactivity disorder (ADHD) without outbursts (ADHD; n = 18). Additional analyses compared results to a sample of healthy children (HC; n = 18) and examined specific associations with behavioral and emotional dysregulation. Compared to the ADHD group, STO children exhibited reduced iFC between the aMCC and surrounding regions of the ACC, and increased iFC between the aMCC and precuneus. These differences were also seen between the STO and HC groups; ADHD and HC groups did not differ. Specificity analyses found associations between aMCC–ACC connectivity and hyperactivity, and between aMCC–precuneus iFC and emotion dysregulation. Disruption in aMCC networks may underlie the behavioral and emotional dysregulation characteristic of children with STO.


Author(s):  
J.P. Owen ◽  
D.P. Wipf ◽  
H.T. Attias ◽  
K. Sekihara ◽  
S.S. Nagarajan

e-Neuroforum ◽  
2017 ◽  
Vol 23 (3) ◽  
Author(s):  
Alexander Groh ◽  
Rebecca Mease ◽  
Patrik Krieger

AbstractThe transduction of painful stimuli into the experience of pain involves several peripheral and central signaling pathways of the nervous system. The organization of these pathways parallels the main functions of pain: the assessment of noxious stimuli (where, what, how strong), and the negative emotion of unpleasantness. Multiple lines of evidence suggest that the thalamocortical (TC) system, which interprets ascending pain signals, has two main pathways which support these functions. We discuss the structural and functional findings that support the view that the lateral TC pathway is involved in discriminative assessment of pain, while the medial TC pathway gives rise to aversive emotions associated with pain. Our review focuses on acute pain, but we also discuss putative TC maladaptations in humans and animal models of pain that are thought to underlie pathological pain sensations.


2021 ◽  
Vol 118 (15) ◽  
pp. e2014464118
Author(s):  
Jill M. Goldstein ◽  
Justine E. Cohen ◽  
Klara Mareckova ◽  
Laura Holsen ◽  
Susan Whitfield-Gabrieli ◽  
...  

Stress is associated with numerous chronic diseases, beginning in fetal development with in utero exposures (prenatal stress) impacting offspring’s risk for disorders later in life. In previous studies, we demonstrated adverse maternal in utero immune activity on sex differences in offspring neurodevelopment at age seven and adult risk for major depression and psychoses. Here, we hypothesized that in utero exposure to maternal proinflammatory cytokines has sex-dependent effects on specific brain circuitry regulating stress and immune function in the offspring that are retained across the lifespan. Using a unique prenatal cohort, we tested this hypothesis in 80 adult offspring, equally divided by sex, followed from in utero development to midlife. Functional MRI results showed that exposure to proinflammatory cytokines in utero was significantly associated with sex differences in brain activity and connectivity during response to negative stressful stimuli 45 y later. Lower maternal TNF-α levels were significantly associated with higher hypothalamic activity in both sexes and higher functional connectivity between hypothalamus and anterior cingulate only in men. Higher prenatal levels of IL-6 were significantly associated with higher hippocampal activity in women alone. When examined in relation to the anti-inflammatory effects of IL-10, the ratio TNF-α:IL-10 was associated with sex-dependent effects on hippocampal activity and functional connectivity with the hypothalamus. Collectively, results suggested that adverse levels of maternal in utero proinflammatory cytokines and the balance of pro- to anti-inflammatory cytokines impact brain development of offspring in a sexually dimorphic manner that persists across the lifespan.


2019 ◽  
Author(s):  
Magdalena Fafrowicz ◽  
Bartosz Bohaterewicz ◽  
Anna Ceglarek ◽  
Monika Cichocka ◽  
Koryna Lewandowska ◽  
...  

Human performance, alertness, and most biological functions express rhythmic fluctuations across a 24-hour-period. This phenomenon is believed to originate from differences in both circadian and homeostatic sleep-wake regulatory processes. Interactions between these processes result in time-of-day modulations of behavioral performance as well as brain activity patterns. Although the basic mechanism of the 24-hour clock is conserved across evolution, there are interindividual differences in the timing of sleep-wake cycles, subjective alertness and functioning throughout the day. The study of circadian typology differences has increased during the last few years, especially research on extreme chronotypes, which provide a unique way to investigate the effects of sleep-wake regulation on cerebral mechanisms. Using functional magnetic resonance imaging (fMRI), we assessed the influence of chronotype and time-of-day on resting-state functional connectivity. 29 extreme morning- and 34 evening-type participants underwent two fMRI sessions: about one hour after wake-up time (morning) and about ten hours after wake-up time (evening), scheduled according to their declared habitual sleep-wake pattern on a regular working day. Analysis of obtained neuroimaging data disclosed only an effect of time of day on resting-state functional connectivity; there were different patterns of functional connectivity between morning and evening sessions. The results of our study showed no differences between extreme morning-type and evening-type individuals. We demonstrate that circadian and homeostatic influences on the resting-state functional connectivity have a universal character, unaffected by circadian typology.


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