scholarly journals Do we really understand the role of the prefrontal cortex in placebo analgesia?

2021 ◽  
Author(s):  
Eleni Frangos ◽  
Nicholas Madian ◽  
Binquan Wang ◽  
Megan L. Bradson ◽  
John L. Gracely ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Pain Relief ◽  
Conditioning Session ◽  
High Heat ◽  
Placebo Analgesia ◽  
Noxious Heat ◽  
Prefrontal Cortical ◽  
Area Functional ◽  
Pain Ratings ◽  
Negative Bold

Several reviews have strongly implicated prefrontal cortical engagement in expectation-based placebo analgesia. We recently found a robust placebo analgesic response and associated decreases in pain-related cortical activations, without observable prefrontal engagement. We hypothesized our substantial conditioning and weak verbal instructions diminished expectation-related prefrontal activation. To test this, we examined the same subjects during a conditioning procedure, in which expectancy of pain relief was high. In two conditioning sessions, noxious heat was applied to a leg region treated with an ″analgesic″ cream and another treated with a ″moisturizing″ cream. In reality, both creams were inert, but the temperature applied to the moisturizing-cream area was 2°C higher than that applied to the analgesic-cream area. Functional MRI was acquired during the second conditioning session. Pain ratings were lower for the low heat than the high heat, with corresponding reduced activations in pain-related regions. Similar to previous studies with strong expectation for pain relief, we observed more prefrontal activations during the ″analgesic″ than the control condition. Nevertheless, contrary to the idea of active prefrontal engagement, the relative activation was based on differences in negative BOLD signals. A literature review revealed that only a few studies conclusively showed active engagement of prefrontal cortex, i.e. increased positive BOLD signal during high expectation compared to a control, with variable timing and spatial-specificity. We suggest that this variability is due to the heterogeneous influence of cognitive, emotional and motivational factors. Future studies should attempt to unravel the multiple contributions to placebo responsiveness in the prefrontal cortex.

scholarly journals The Role of Primate Prefrontal Cortex in Bias and Shift Between Visual Dimensions

2019 ◽  
Vol 30 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Farshad A Mansouri ◽  
Mark J Buckley ◽  
Daniel J Fehring ◽  
Keiji Tanaka
Keyword(s):  
Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Top Down ◽  
Attentional Processes ◽  
Prefrontal Cortical ◽  
Frontopolar Cortex ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions ◽  
Visual Cortical ◽  
Bilateral Lesions

Abstract Imaging and neural activity recording studies have shown activation in the primate prefrontal cortex when shifting attention between visual dimensions is necessary to achieve goals. A fundamental unanswered question is whether representations of these dimensions emerge from top-down attentional processes mediated by prefrontal regions or from bottom-up processes within visual cortical regions. We hypothesized a causative link between prefrontal cortical regions and dimension-based behavior. In large cohorts of humans and macaque monkeys, performing the same attention shifting task, we found that both species successfully shifted between visual dimensions, but both species also showed a significant behavioral advantage/bias to a particular dimension; however, these biases were in opposite directions in humans (bias to color) versus monkeys (bias to shape). Monkeys’ bias remained after selective bilateral lesions within the anterior cingulate cortex (ACC), frontopolar cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), or superior, lateral prefrontal cortex. However, lesions within certain regions (ACC, DLPFC, or OFC) impaired monkeys’ ability to shift between these dimensions. We conclude that goal-directed processing of a particular dimension for the executive control of behavior depends on the integrity of prefrontal cortex; however, representation of competing dimensions and bias toward them does not depend on top-down prefrontal-mediated processes.

scholarly journals Intolerance of uncertainty is associated with heightened responding in the prefrontal cortex during instructed threat of shock

2020 ◽  
Author(s):  
Jayne Morriss ◽  
Tiffany Bell ◽  
Nicolò Biagi ◽  
Tom Johnstone ◽  
Carien M. van Reekum
Keyword(s):  
Prefrontal Cortex ◽  
Anxiety Disorder ◽  
Intolerance Of Uncertainty ◽  
Neural Circuitry ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Prefrontal Cortical ◽  
Cortical Regions ◽  
Rostral Prefrontal Cortex ◽  
Threat Of Shock

AbstractHeightened responding to uncertain threat is associated with anxiety disorder pathology. Here, we sought to determine if individual differences in self-reported intolerance of uncertainty (IU) underlie differential recruitment of neural circuitry during instructed threat of shock (n = 42). During the task, cues signalled uncertain threat of shock (50%) or certain safety from shock. Ratings, skin conductance and functional magnetic resonance imaging was acquired. Overall, participants displayed greater amygdala activation to uncertain threat vs. safe cues, in the absence of an effect of IU. However, we found that high was associated with greater activity in the medial prefrontal cortex and dorsomedial rostral prefrontal cortex to uncertain threat vs safe cues. These findings suggest that, during instructed threat of shock, IU is specifically related, over trait anxiety, to activation in prefrontal cortical regions. Taken together, these findings highlight the potential of self-reported IU in identifying mechanisms that may be related to conscious threat appraisal and anxiety disorder pathology.

scholarly journals Prefrontal Cortical Response to Conflict during Semantic and Phonological Tasks

2007 ◽  
Vol 19 (5) ◽  
pp. 761-775 ◽  
Author(s):  
Hannah R. Snyder ◽  
Keith Feigenson ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Control ◽  
Phonological Processing ◽  
Functional Organization ◽  
Inferior Frontal Gyrus ◽  
General Function ◽  
Left Inferior Frontal Gyrus ◽  
Domain Specific ◽  
Prefrontal Cortical ◽  
Specific Effects

Debates about the function of the prefrontal cortex are as old as the field of neuropsychology—often dated to Paul Broca's seminal work. Theories of the functional organization of the prefrontal cortex can be roughly divided into those that describe organization by process and those that describe organization by material. Recent studies of the function of the posterior, left inferior frontal gyrus (pLIFG) have yielded two quite different interpretations: One hypothesis holds that the pLIFG plays a domain-specific role in phonological processing, whereas another hypothesis describes a more general function of the pLIFG in cognitive control. In the current study, we distinguish effects of increasing cognitive control demands from effects of phonological processing. The results support the hypothesized role for the pLIFG in cognitive control, and more task-specific roles for posterior areas in phonology and semantics. Thus, these results suggest an alternative explanation of previously reported phonology-specific effects in the pLIFG.

scholarly journals Mechanistic link between right prefrontal cortical activity and anxious arousal revealed using transcranial magnetic stimulation in healthy subjects

2019 ◽  
Vol 45 (4) ◽  
pp. 694-702 ◽  
Author(s):  
Nicholas L. Balderston ◽  
Emily M. Beydler ◽  
Camille Roberts ◽  
Zhi-De Deng ◽  
Thomas Radman ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Subcortical Structures ◽  
Prefrontal Cortical ◽  
Dorsolateral Prefrontal ◽  
Before And After ◽  
The Right

AbstractMuch of the mechanistic research on anxiety focuses on subcortical structures such as the amygdala; however, less is known about the distributed cortical circuit that also contributes to anxiety expression. One way to learn about this circuit is to probe candidate regions using transcranial magnetic stimulation (TMS). In this study, we tested the involvement of the dorsolateral prefrontal cortex (dlPFC), in anxiety expression using 10 Hz repetitive TMS (rTMS). In a within-subject, crossover experiment, the study measured anxiety in healthy subjects before and after a session of 10 Hz rTMS to the right dorsolateral prefrontal cortex (dlPFC). It used threat of predictable and unpredictable shock to induce anxiety and anxiety potentiated startle to assess anxiety. Counter to our hypotheses, results showed an increase in anxiety-potentiated startle following active but not sham rTMS. These results suggest a mechanistic link between right dlPFC activity and physiological anxiety expression. This result supports current models of prefrontal asymmetry in affect, and lays the groundwork for further exploration into the cortical mechanisms mediating anxiety, which may lead to novel anxiety treatments.

scholarly journals Communicating and understanding pain: Limitations of pain scales for patients with sickle cell disorder and other painful conditions

2020 ◽  
pp. 135910532094498 ◽  
Author(s):  
Peter J Collins ◽  
Alicia Renedo ◽  
Cicely A Marston
Keyword(s):  
Pain Relief ◽  
Social Interactions ◽  
Sickle Cell ◽  
Healthcare Professionals ◽  
Clinical Assessments ◽  
Pain Communication ◽  
Pain Scales ◽  
Pain Ratings ◽  
Cell Disorder

Pain communication in healthcare is challenging. We examine use of pain scales to communicate pain severity via a case study of people with sickle cell disorder (SCD). We show how pain communication involves complex social interactions between patients, healthcare professionals and significant others – none of which are included in pain ratings. Failure to account for relational aspects of pain may cause problems for any patient. For SCD, mutual distrust shapes pain communication, further complicating clinical assessments. Moreover, SCD pain is particularly severe, making ratings hard to interpret compared with ratings from non-SCD patients, potentially exacerbating problems in managing pain relief.

Prefrontal cortex modulates placebo analgesia

Pain ◽  
2010 ◽  
Vol 148 (3) ◽  
pp. 368-374 ◽  
Author(s):  
Peter Krummenacher ◽  
Victor Candia ◽  
Gerd Folkers ◽  
Manfred Schedlowski ◽  
Georg Schönbächler
Keyword(s):  
Prefrontal Cortex ◽  
Placebo Analgesia

FROST: A Distributed Neurocomputational Model of Working Memory Maintenance

2005 ◽  
Vol 17 (11) ◽  
pp. 1728-1743 ◽  
Author(s):  
F. Gregory Ashby ◽  
Shawn W. Ell ◽  
Vivian V. Valentin ◽  
Michael B. Casale
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Caudate Nucleus ◽  
Globus Pallidus ◽  
Posterior Parietal Cortex ◽  
Distributed Network ◽  
Prefrontal Cortical ◽  
Cell Recording ◽  
Posterior Parietal ◽  
Cortical Excitation

Many studies suggest that the sustained activation underlying working memory (WM) maintenance is mediated by a distributed network that includes the prefrontal cortex and other structures (e.g., posterior parietal cortex, thalamus, globus pallidus, and the caudate nucleus). A computational model of WM, called FROST (short for FROntal-Striatal-Thalamic), is proposed in which the representation of items and spatial positions is encoded in the lateral prefrontal cortex. During delay intervals, activation in these prefrontal cells is sustained via parallel, prefrontal cortical-thalamic loops. Activation reverberates in these loops because prefrontal cortical excitation of the head of the caudate nucleus leads to disinhibition of the thalamus (via the globus pallidus). FROST successfully accounts for a wide variety of WM data, including single-cell recording data and human behavioral data.

Comparison of prefrontal architecture and connections

1996 ◽  
Vol 351 (1346) ◽  
pp. 1423-1432 ◽  
Keyword(s):  
Prefrontal Cortex ◽  
Rhesus Monkeys ◽  
New Technology ◽  
Morphological Characteristics ◽  
Imaging Studies ◽  
Precise Information ◽  
Functional Roles ◽  
Cortical Areas ◽  
Prefrontal Cortical ◽  
Morphological Organization

The advent of new technology has led to a proliferation of studies examining the functional roles of discrete prefrontal cortical areas. This has created a need for more precise information regarding the morphological characteristics of this region. Existing architectonic maps of human and monkey brains are not compatible with regard to areal delineations and topography, creating significant difficulty in interpreting comparative data. Therefore, we have re-examined the comparative morphological organization of the prefrontal cortex in humans and rhesus monkeys. Our analysis indicates that the architectonic areas in both species correspond in terms of morphological features as well as topographical locations. We have developed a common organizational schema for these areas, thereby allowing for a resolution of previous discrepancies. Moreover, in monkeys a connectional analysis has revealed that each of the newly designated areas is characterized by a unique pattern of cortical relationships. The present organizational schema provides a framework for interrelating findings such as those obtained from human brain imaging studies with those from behavioural investigations of non-human primates.

Morphine Inhibits Acetylcholine Release in Rat Prefrontal Cortex When Delivered Systemically or by Microdialysis to Basal Forebrain

2005 ◽  
Vol 103 (4) ◽  
pp. 779-787 ◽  
Author(s):  
Nadir I. Osman ◽  
Helen A. Baghdoyan ◽  
Ralph Lydic
Keyword(s):  
Prefrontal Cortex ◽  
Basal Forebrain ◽  
Acetylcholine Release ◽  
Sprague Dawley ◽  
Guide Cannula ◽  
Microdialysis Probe ◽  
Prefrontal Cortical ◽  
Substantia Innominata ◽  
Morphine Administration ◽  
Intravenous Morphine

Background Cortical acetylcholine originates in the basal forebrain and is essential for maintaining normal cognition and arousal. Morphine impairs these cholinergically mediated cortical functions. The current study tested the hypothesis that morphine decreases prefrontal cortical acetylcholine release by acting at the level of the basal forebrain. Methods Adult male Sprague-Dawley rats (n = 18) were anesthetized with isoflurane. One microdialysis probe was placed in the substantia innominata region of the basal forebrain and perfused with Ringer's solution (control) followed by one concentration of morphine (1, 10, 100, or 1,000 microm) or morphine (1,000 microm) plus naloxone (100 microm). A second microdialysis probe was placed in the prefrontal cortex for measuring acetylcholine. In a second series of experiments, rats (n = 6) were implanted with electrodes for recording states of arousal, a guide cannula positioned above the prefrontal cortex for inserting a microdialysis probe, and an indwelling jugular vein catheter. The effects of administering intravenous morphine (30 mg/kg) versus normal saline (0.9%) on prefrontal cortical acetylcholine release, cortical electroencephalographic power, and behavior were quantified. Results Dialysis delivery of morphine to the substantia innominata caused a concentration-dependent, naloxone-sensitive decrease in acetylcholine release within the prefrontal cortex. The maximal decrease in acetylcholine was 36.3 +/- 11.5%. Intravenous morphine administration significantly decreased cortical acetylcholine release, increased electroencephalographic power in the 0.5- to 5-Hz range, and eliminated normal wakefulness. Conclusion Morphine causes obtundation of arousal and may cause cognitive impairment by acting at the level of the substantia innominata to disrupt cortical cholinergic neurotransmission.

scholarly journals Extended reality for chronic pain relief

2020 ◽  
Author(s):  
J Wang ◽  
Craig Anslow ◽  
Brian Robinson ◽  
Simon McCallum
Keyword(s):  
Chronic Pain ◽  
Pain Relief ◽  
Body Movement ◽  
Daily Lives ◽  
Chronic Pain Patients ◽  
Pain Ratings ◽  
Subjective Pain ◽  
Initial Injury ◽  
Physical Interactions ◽  
Pain Patients

© 2019 Copyright held by the owner/author(s). Chronic pain is ongoing pain lasting for long periods of time after the initial injury or disease has healed. Chronic pain is difficult to treat and can affect the daily lives of patients. Distraction therapy is a proven way of relieving pain by redirecting the focus of patients' attention. Virtual reality is an effective platform for distraction therapy as it immerses the user visually, aurally, and even somewhat physically in a virtual world detached from reality. There is little research done on the effects that physical interactions have on pain management. This project aims to evaluate different types of extended reality (XR) interactions, including full body movement, for chronic pain patients to determine which is the best for pain relief. We are building a prototype for participants to interact both mentally and physically and measuring the reduction in subjective pain ratings at various points of the XR experience.

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