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Huneke NTM, Cross C, Fagan HA, Molteni L, Phillips N, Garner M, Baldwin DS. Placebo Effects Are Small on Average in the 7.5% CO2 Inhalational Model of Generalized Anxiety. Int J Neuropsychopharmacol 2024; 27:pyae019. [PMID: 38577951 PMCID: PMC11059817 DOI: 10.1093/ijnp/pyae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 04/10/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Anxiety disorders are highly prevalent and socio-economically costly. Novel pharmacological treatments for these disorders are needed because many patients do not respond to current agents or experience unwanted side effects. However, a barrier to treatment development is the variable and large placebo response rate seen in trials of novel anxiolytics. Despite this, the mechanisms that drive placebo responses in anxiety disorders have been little investigated, possibly due to low availability of convenient experimental paradigms. We aimed to develop and test a novel protocol for inducing placebo anxiolysis in the 7.5% CO2 inhalational model of generalized anxiety in healthy volunteers. METHODS Following a baseline 20-minute CO2 challenge, 32 healthy volunteers were administered a placebo intranasal spray labelled as either the anxiolytic "lorazepam" or "saline." Following this, participants surreptitiously underwent a 20-minute inhalation of normal air. Post-conditioning, a second dose of the placebo was administered, after which participants completed another CO2 challenge. RESULTS Participants administered sham "lorazepam" reported significant positive expectations of reduced anxiety (P = .001), but there was no group-level placebo effect on anxiety following CO2 challenge post-conditioning (Ps > .350). Surprisingly, we found many participants exhibited unexpected worsening of anxiety, despite positive expectations. CONCLUSIONS Contrary to our hypothesis, our novel paradigm did not induce a placebo response, on average. It is possible that effects of 7.5% CO2 inhalation on prefrontal cortex function or behavior in line with a Bayesian predictive coding framework attenuated the effect of expectations on subsequent placebo response. Future studies are needed to explore these possibilities.
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Affiliation(s)
- Nathan T M Huneke
- Southern Health National Health Service Foundation Trust, Southampton, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK
- University Department of Psychiatry, Academic Centre, College Keep, Southampton, UK
| | - Cosmina Cross
- Southern Health National Health Service Foundation Trust, Southampton, UK
| | - Harry A Fagan
- Southern Health National Health Service Foundation Trust, Southampton, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK
- University Department of Psychiatry, Academic Centre, College Keep, Southampton, UK
| | - Laura Molteni
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK
- University Department of Psychiatry, Academic Centre, College Keep, Southampton, UK
| | | | - Matthew Garner
- Center for Innovation in Mental Health, School of Psychology, Faculty of Environmental and Life Sciences, University of Southampton, UK
- University Department of Psychiatry, Academic Centre, College Keep, Southampton, UK
| | - David S Baldwin
- University Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
- Southern Health National Health Service Foundation Trust, Southampton, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK
- University Department of Psychiatry, Academic Centre, College Keep, Southampton, UK
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2
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The Respiratory Resistance Sensitivity Task: An Automated Method for Quantifying Respiratory Interoception and Metacognition. Biol Psychol 2022; 170:108325. [DOI: 10.1016/j.biopsycho.2022.108325] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 12/17/2022]
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3
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Wiese AD, Boutros NN. Diagnostic Utility of Sodium Lactate Infusion and CO2-35% Inhalation for Panic Disorder. Neuropsychobiology 2019; 78:59-69. [PMID: 30982042 DOI: 10.1159/000499136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 02/26/2019] [Indexed: 11/19/2022]
Abstract
Laboratory measures have played an integral role in diagnosing pathology; however, compared to traditional medicine, psychiatric medicine has lagged behind in using such measures. A growing body of literature has begun to examine the viability and development of different laboratory measures in order to diagnose psychopathologies. The present review examines the current state of development of both sodium lactate infusion and CO2-35% inhalation as potential ancillary measures to diagnose panic disorder (PD). A previously established 3-step approach to identifying laboratory-based diagnostic tests was applied to available literature assessing the ability of both sodium lactate infusion or CO2-35% inhalation to induce panic attacks in PD patients, healthy controls, and individuals with other psychiatric conditions. Results suggest that across the literature reviewed, individuals with PD were more likely to exhibit panic attacks following administration of sodium lactate or CO2-35% compared to control participants. The majority of the studies examined only compared individuals with PD to healthy controls, suggesting that these ancillary measures are underdeveloped. In order to further determine the utility of these ancillary measures, research is needed to determine if panic attacks following administration of these chemical agents are unique to PD, or if individuals with related pathologies also respond, which may be indicative of transdiagnostic characteristics found across disorders.
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Affiliation(s)
- Andrew D Wiese
- Department of Psychology, University of Missouri-Kansas City, Kansas City, Missouri, USA.,Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Nash N Boutros
- Behavioral Neurology Division, Saint Luke's Marion Bloch Neuroscience Institute, Kansas City, Missouri, USA, .,Department of Psychiatry, University of Missouri-Kansas City, Kansas City, Missouri, USA,
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4
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Zaman J, Van de Pavert I, Van Oudenhove L, Van Diest I. The use of stimulus perception to account for variability in skin conductance responses to interoceptive stimuli. Psychophysiology 2019; 57:e13494. [PMID: 31608999 DOI: 10.1111/psyp.13494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/05/2019] [Accepted: 07/02/2019] [Indexed: 01/27/2023]
Abstract
Activity of the electrodermal response system is customarily expressed in relation to physical stimulus properties and not to perceived features. In situations where the delivery of physically identical stimuli can be challenging, such as in interoception research, this variability might pose a challenge for contemporary SCR analyses. Therefore, we investigated the extent to which activity in the electrodermal response system triggered by the delivery of interoceptive stimuli is better predicted by perceived intensity rather than physical input. For this purpose, we reanalyzed data from the baseline phase of a previous study (n = 60) in which skin conductance responses (SCRs) to innocuous esophageal stimulations of high and low intensities were recorded in addition to categorizations based on their perceived intensity (high or low). Using both peak scoring and model inversion methods, we found that the inclusion of stimulus perception as a predictor of the magnitude of the SCR increased model fit. These findings suggest that the inclusion of perception is a promising avenue to better model variability in psychophysiological responses to interoceptive stimuli.
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Affiliation(s)
- Jonas Zaman
- Department of Health Psychology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium.,Center for the Psychology of Learning and Experimental Psychopathology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
| | - Iris Van de Pavert
- Department of Health Psychology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
| | - Lukas Van Oudenhove
- Laboratory for Brain-Gut Axis Studies (LaBGAS), Translational Research Centre for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism, and Ageing, KU Leuven, Leuven, Belgium.,Consultation-Liaison Psychiatry, University Psychiatric Centre KU Leuven, Leuven, Belgium
| | - Ilse Van Diest
- Department of Health Psychology, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
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5
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Van Diest I. Interoception, conditioning, and fear: The panic threesome. Psychophysiology 2019; 56:e13421. [DOI: 10.1111/psyp.13421] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/11/2019] [Accepted: 05/16/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Ilse Van Diest
- Health, Behavior & Psychopathology, Faculty of Psychology & Educational Sciences; University of Leuven; Leuven Belgium
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7
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Balderston NL, Liu J, Roberson-Nay R, Ernst M, Grillon C. The relationship between dlPFC activity during unpredictable threat and CO 2-induced panic symptoms. Transl Psychiatry 2017; 7:1266. [PMID: 29213110 PMCID: PMC5802456 DOI: 10.1038/s41398-017-0006-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 01/08/2023] Open
Abstract
Panic disorder is characterized by sudden, repeated, and unexpected attacks of intense fear and overwhelming anxiety about when another attack may strike. Patients with panic disorder and healthy individuals with a history of panic attacks show a hypersensitivity to unpredictable threats, suggesting a possible link between panic and sustained anxiety. The purpose of this study was to determine the degree to which induced symptoms of panic relate to fear and anxiety, as well as activity in the neural systems that mediate and regulate these affective states. Psychological and physiological symptoms of panic were assessed during an 8-min 7.5% CO2 challenge task. Psychological, physiological, and neural symptoms of fear and anxiety were measured during two sessions (one psychophysiology and one functional magnetic resonance imaging where subjects experienced several blocks of no threat (N), predictable shock (P), and unpredictable shock (U; NPU threat task). We used a principle component analysis to characterize panic susceptibility (PS), and found that PS significantly predicted dorsolateral prefrontal cortex (dlPFC) activity to the unpredictable cue during the NPU threat task. When examining the weighted beta coefficients from this analysis, we observed that self-reported fear/anxiety during the CO2 challenge negatively loaded onto dlPFC activity during the NPU task. Consistent with this observation, dlPFC activity during the unpredictable cue was also negatively correlated with anxiety during the NPU sessions. Together, these results suggest that panic symptoms and anxiety are regulated by the same prefrontal cognitive control system.
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Affiliation(s)
- Nicholas L. Balderston
- 0000 0001 2297 5165grid.94365.3dSection on Neurobiology of Fear and Anxiety, National Institute of Mental Health, National Institutes of Health, Bethesda, MD USA
| | - Jeffrey Liu
- 0000 0001 2297 5165grid.94365.3dSection on Neurobiology of Fear and Anxiety, National Institute of Mental Health, National Institutes of Health, Bethesda, MD USA
| | - Roxann Roberson-Nay
- 0000 0004 0458 8737grid.224260.0Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond, VA USA
| | - Monique Ernst
- 0000 0001 2297 5165grid.94365.3dSection on Neurobiology of Fear and Anxiety, National Institute of Mental Health, National Institutes of Health, Bethesda, MD USA
| | - Christian Grillon
- 0000 0001 2297 5165grid.94365.3dSection on Neurobiology of Fear and Anxiety, National Institute of Mental Health, National Institutes of Health, Bethesda, MD USA
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8
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Schulz A, van Dyck Z, Lutz AP, Rost S, Vögele C. Gastric modulation of startle eye blink. Biol Psychol 2017; 127:25-33. [DOI: 10.1016/j.biopsycho.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 05/04/2017] [Accepted: 05/04/2017] [Indexed: 01/04/2023]
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Janssens T, Caris E, Van Diest I, Van den Bergh O. Learning to Detect Triggers of Airway Symptoms: The Role of Illness Beliefs, Conceptual Categories and Actual Experience with Allergic Symptoms. Front Psychol 2017. [PMID: 28638358 PMCID: PMC5461359 DOI: 10.3389/fpsyg.2017.00926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background: In asthma and allergic rhinitis, beliefs about what triggers allergic reactions often do not match objective allergy tests. This may be due to insensitivity for expectancy violations as a result of holding trigger beliefs based on conceptual relationships among triggers. In this laboratory experiment, we aimed to investigate how pre-existing beliefs and conceptual relationships among triggers interact with actual experience when learning differential symptom expectations. Methods: Healthy participants (N = 48) received information that allergic reactions were a result of specific sensitivities versus general allergic vulnerability. Next, they performed a trigger learning task using a differential conditioning paradigm: brief inhalation of CO2 enriched air was used to induce symptoms, while participants were led to believe that the symptoms came about as a result of inhaled allergens (conditioned stimuli, CS’s; CS+ followed by symptoms, CS- not followed by symptoms). CS+ and CS- stimuli either shared (e.g., birds-mammals) or did not share (e.g. birds-fungi) category membership. During Acquisition, participants reported symptom expectancy and symptom intensity for all triggers. During a Test 1 day later, participants rated symptom expectancies for old CS+/CS- triggers, for novel triggers within categories, and for exemplars of novel trigger categories. Data were analyzed using multilevel models. Findings: Only a subgroup of participants (n = 22) showed differences between CO2 and room air symptoms. In this group of responders, analysis of symptom expectancies during acquisition did not result in significant differential symptom CS+/CS- acquisition. A retention test 1 day later showed differential CS+/CS- symptom expectancies: When CS categories did not share category membership, specific sensitivity beliefs improved retention of CS+/CS- differentiation. However, when CS categories shared category membership, general vulnerability beliefs improved retention of CS+/CS- differentiation. Furthermore, participants showed some selectivity in generalization of symptom expectancies to novel categories, as symptom expectancies did not generalize to novel categories that were unrelated to CS+ or CS- categories. Generalization to novel categories was not affected by information about general vulnerability or specific sensitivities. Discussion: Pre-existing vulnerability beliefs and conceptual relationships between trigger categories influence differential symptom expectancies to allergic triggers.
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Affiliation(s)
| | - Eva Caris
- Health Psychology, KU LeuvenLeuven, Belgium
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10
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Schulz A, Schilling TM, Vögele C, Larra MF, Schächinger H. Respiratory modulation of startle eye blink: a new approach to assess afferent signals from the respiratory system. Philos Trans R Soc Lond B Biol Sci 2016; 371:rstb.2016.0019. [PMID: 28080976 DOI: 10.1098/rstb.2016.0019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2016] [Indexed: 11/12/2022] Open
Abstract
Current approaches to assess interoception of respiratory functions cannot differentiate between the physiological basis of interoception, i.e. visceral-afferent signal processing, and the psychological process of attention focusing. Furthermore, they typically involve invasive procedures, e.g. induction of respiratory occlusions or the inhalation of CO2-enriched air. The aim of this study was to test the capacity of startle methodology to reflect respiratory-related afferent signal processing, independent of invasive procedures. Forty-two healthy participants were tested in a spontaneous breathing and in a 0.25 Hz paced breathing condition. Acoustic startle noises of 105 dB(A) intensity (50 ms white noise) were presented with identical trial frequency at peak and on-going inspiration and expiration, based on a new pattern detection method, involving the online processing of the respiratory belt signal. The results show the highest startle magnitudes during on-going expiration compared with any other measurement points during the respiratory cycle, independent of whether breathing was spontaneous or paced. Afferent signals from slow adapting phasic pulmonary stretch receptors may be responsible for this effect. This study is the first to demonstrate startle modulation by respiration. These results offer the potential to apply startle methodology in the non-invasive testing of interoception-related aspects in respiratory psychophysiology.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
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Affiliation(s)
- André Schulz
- Institute for Health and Behaviour, Research Unit INSIDE, University of Luxembourg, 11, Porte des Sciences, 4366 Esch-sur-Alzette, Luxembourg .,Division of Clinical Psychophysiology, Institute of Psychobiology, University of Trier, Johanniterufer 15, 54290 Trier, Germany
| | - Thomas M Schilling
- Division of Clinical Psychophysiology, Institute of Psychobiology, University of Trier, Johanniterufer 15, 54290 Trier, Germany
| | - Claus Vögele
- Institute for Health and Behaviour, Research Unit INSIDE, University of Luxembourg, 11, Porte des Sciences, 4366 Esch-sur-Alzette, Luxembourg
| | - Mauro F Larra
- Division of Clinical Psychophysiology, Institute of Psychobiology, University of Trier, Johanniterufer 15, 54290 Trier, Germany
| | - Hartmut Schächinger
- Division of Clinical Psychophysiology, Institute of Psychobiology, University of Trier, Johanniterufer 15, 54290 Trier, Germany
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11
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Button KS, Karwatowska L, Kounali D, Munafò MR, Attwood AS. Acute anxiety and social inference: An experimental manipulation with 7.5% carbon dioxide inhalation. J Psychopharmacol 2016; 30:1036-46. [PMID: 27380750 PMCID: PMC5036074 DOI: 10.1177/0269881116653105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Positive self-bias is thought to be protective for mental health. We previously found that the degree of positive bias when learning self-referential social evaluation decreases with increasing social anxiety. It is unclear whether this reduction is driven by differences in state or trait anxiety, as both are elevated in social anxiety; therefore, we examined the effects on the state of anxiety induced by the 7.5% carbon dioxide (CO2) inhalation model of generalised anxiety disorder (GAD) on social evaluation learning. METHODS For our study, 48 (24 of female gender) healthy volunteers took two inhalations (medical air and 7.5% CO2, counterbalanced) whilst learning social rules (self-like, self-dislike, other-like and other-dislike) in an instrumental social evaluation learning task. We analysed the outcomes (number of positive responses and errors to criterion) using the random effects Poisson regression. RESULTS Participants made fewer and more positive responses when breathing 7.5% CO2 in the other-like and other-dislike rules, respectively (gas × condition × rule interaction p = 0.03). Individuals made fewer errors learning self-like than self-dislike, and this positive self-bias was unaffected by CO2. Breathing 7.5% CO2 increased errors, but only in the other-referential rules (gas × condition × rule interaction p = 0.003). CONCLUSIONS Positive self-bias (i.e. fewer errors learning self-like than self-dislike) seemed robust to changes in state anxiety. In contrast, learning other-referential evaluation was impaired as state anxiety increased. This suggested that the previously observed variations in self-bias arise due to trait, rather than state, characteristics.
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Affiliation(s)
| | - Lucy Karwatowska
- UK Centre for Tobacco and Alcohol Studies, School of Experimental Psychology, University of Bristol, Bristol, UK
| | - Daphne Kounali
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Marcus R Munafò
- UK Centre for Tobacco and Alcohol Studies, School of Experimental Psychology, University of Bristol, Bristol, UK,Integrative Epidemiology Unit, Medical Research Council, University of Bristol, Bristol, UK
| | - Angela S Attwood
- UK Centre for Tobacco and Alcohol Studies, School of Experimental Psychology, University of Bristol, Bristol, UK,Integrative Epidemiology Unit, Medical Research Council, University of Bristol, Bristol, UK
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12
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13
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Effects of anxiety sensitivity and expectations on the modulation of the startle eyeblink response during a caffeine challenge. Psychopharmacology (Berl) 2015; 232:3403-16. [PMID: 26173609 DOI: 10.1007/s00213-015-3996-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/10/2015] [Indexed: 10/23/2022]
Abstract
RATIONALE The way in which the tendency to fear somatic arousal sensations (anxiety sensitivity), in interaction with the created expectations regarding arousal induction, might affect defensive responding to a symptom provocation challenge is not yet understood. OBJECTIVES The present study investigated the effect of anxiety sensitivity on autonomic arousal, startle eyeblink responses, and reported arousal and alertness to expected vs. unexpected caffeine consumption. METHODS To create a match/mismatch of expected and experienced arousal, high and low anxiety sensitive participants received caffeine vs. no drug either mixed in coffee (expectation of arousal induction) or in bitter lemon soda (no expectation of arousal induction) on four separate occasions. Autonomic arousal (heart rate, skin conductance level), respiration (end-tidal CO2, minute ventilation), defensive reflex responses (startle eyeblink), and reported arousal and alertness were recorded prior to, immediately and 30 min after beverage ingestion. RESULTS Caffeine increased ventilation, autonomic arousal, and startle response magnitudes. Both groups showed comparable levels of autonomic and respiratory responses. The startle eyeblink responses were decreased when caffeine-induced arousal occurred unexpectedly, e.g., after administering caffeine in bitter lemon. This effect was more accentuated in high anxiety sensitive persons. Moreover, in high anxiety sensitive persons, the expectation of arousal (coffee consumption) led to higher subjective alertness when administering caffeine and increased arousal even if no drug was consumed. CONCLUSIONS Unexpected symptom provocation leads to increased attention allocation toward feared arousal sensations in high anxiety sensitive persons. This finding broadens our understanding of modulatory mechanisms in defensive responding to bodily symptoms.
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Pinkney V, Wickens R, Bamford S, Baldwin DS, Garner M. Defensive eye-blink startle responses in a human experimental model of anxiety. J Psychopharmacol 2014; 28:874-80. [PMID: 24899597 PMCID: PMC4876426 DOI: 10.1177/0269881114532858] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Inhalation of low concentrations of carbon dioxide (CO2) triggers anxious behaviours in rodents via chemosensors in the amygdala, and increases anxiety, autonomic arousal and hypervigilance in healthy humans. However, it is not known whether CO2 inhalation modulates defensive behaviours coordinated by this network in humans. We examined the effect of 7.5% CO2 challenge on the defensive eye-blink startle response. A total of 27 healthy volunteers completed an affective startle task during inhalation of 7.5% CO2 and air. The magnitude and latency of startle eye-blinks were recorded whilst participants viewed aversive and neutral pictures. We found that 7.5% CO2 increased state anxiety and raised concurrent measures of skin conductance and heart rate (HR). CO2 challenge did not increase startle magnitude, but slowed the onset of startle eye-blinks. The effect of CO2 challenge on HR covaried with its effects on both subjective anxiety and startle latency. Our findings are discussed with reference to startle profiles during conditions of interoceptive threat, increased cognitive load and in populations characterised by anxiety, compared with acute fear and panic.
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Affiliation(s)
| | - Robin Wickens
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
| | - Susan Bamford
- Psychology, University of Southampton, Southampton, UK
| | - David S Baldwin
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Matthew Garner
- Psychology, University of Southampton, Southampton, UK Clinical and Experimental Sciences, University of Southampton, Southampton, UK
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Moody CM, Chua B, Weary DM. The effect of carbon dioxide flow rate on the euthanasia of laboratory mice. Lab Anim 2014; 48:298-304. [PMID: 25097256 DOI: 10.1177/0023677214546509] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Laboratory rodents are commonly euthanized by exposure to gradually increasing concentrations of carbon dioxide (CO2). Current recommended flow rates range between 10 and 30% chamber vol/min and result in insensibility before exposure to painful concentrations (<40%). However, this method causes dyspnea, indicated by deep, rapid breathing. In humans dyspnea is associated with a negative affective experience. Sensations of dyspnea may explain why rodents find CO2 concentrations >3% aversive. This study aimed to assess the effect of CO2 flow rates on time between the onset of dyspnea and various measures of insensibility (recumbency, loss of the righting reflex and loss of the pedal withdrawal reflex) to identify flow rates that minimize the potential experience of dyspnea. The results of this study indicate that a flow rate of 50% chamber vol/min, while holding the CO2 cage concentration just below 40%, minimizes the interval between the onset of labored breathing and recumbency. Using a 50% flow rate this interval averaged (± SE) 30.3 ± 2.9 s versus 49.7 ± 2.9 s at 20% chamber vol/min (F3,22 = 7.83, P = 0.0013). Similarly, the interval between the onset of labored breathing and loss of the righting reflex averaged 38.2 ± 2.4 s at a flow rate of 50% versus 59.2 ± 2.4 s at 20% chamber vol/min of CO2 (F3,22 = 13.62, P < 0.0001). We conclude that higher flow rates reduce the duration of dyspnea, but even at the highest flow rate mice experience more than 30 s between the onset of dyspnea and the most conservative estimate of insensibility.
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Affiliation(s)
- C M Moody
- Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
| | - B Chua
- Centre for Comparative Medicine, University of British Columbia, Vancouver, Canada
| | - D M Weary
- Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
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Alius MG, Pané-Farré CA, Löw A, Hamm AO. Modulation of the blink reflex and P3 component of the startle response during an interoceptive challenge. Psychophysiology 2014; 52:140-8. [DOI: 10.1111/psyp.12295] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 06/25/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Manuela G. Alius
- Department of Biological and Clinical Psychology; University of Greifswald; Greifswald Germany
| | | | - Andreas Löw
- Department of Biological and Clinical Psychology; University of Greifswald; Greifswald Germany
| | - Alfons O. Hamm
- Department of Biological and Clinical Psychology; University of Greifswald; Greifswald Germany
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Ceunen E, Zaman J, Vlaeyen JWS, Dankaerts W, Van Diest I. Effect of seated trunk posture on eye blink startle and subjective experience: comparing flexion, neutral upright posture, and extension of spine. PLoS One 2014; 9:e88482. [PMID: 24516664 PMCID: PMC3917889 DOI: 10.1371/journal.pone.0088482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 01/08/2014] [Indexed: 11/18/2022] Open
Abstract
Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes.
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Affiliation(s)
- Erik Ceunen
- Research Group Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium
| | - Jonas Zaman
- Research Group Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium
| | - Johan W. S. Vlaeyen
- Research Group Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium
- Department of Clinical Psychological Science, Maastricht University, Maastricht, The Netherlands
| | - Wim Dankaerts
- Research Group on Musculoskeletal Rehabilitation, KU Leuven (University of Leuven), Leuven, Belgium
| | - Ilse Van Diest
- Research Group Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium
- * E-mail:
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Carbon dioxide inhalation as a human experimental model of panic: The relationship between emotions and cardiovascular physiology. Biol Psychol 2013; 94:331-40. [DOI: 10.1016/j.biopsycho.2013.06.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 05/28/2013] [Accepted: 06/19/2013] [Indexed: 11/23/2022]
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19
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Amaral JMXD, Spadaro PTM, Pereira VM, Silva ACDOE, Nardi AE. The carbon dioxide challenge test in panic disorder: a systematic review of preclinical and clinical research. BRAZILIAN JOURNAL OF PSYCHIATRY 2013; 35:318-31. [DOI: 10.1590/1516-4446-2012-1045] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 12/28/2012] [Indexed: 11/22/2022]
Affiliation(s)
- Julio Mario Xerfan do Amaral
- Universidade Federal do Rio de Janeiro, Brazil; UFRJ, Brazil; National Science and Technology Institute for Translational Medicine
| | - Pedro Tadeu Machado Spadaro
- Universidade Federal do Rio de Janeiro, Brazil; UFRJ, Brazil; National Science and Technology Institute for Translational Medicine
| | | | | | - Antonio Egidio Nardi
- UFRJ, Brazil; National Science and Technology Institute for Translational Medicine
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20
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Atypical modulation of startle in women in face of aversive bodily sensations. Int J Psychophysiol 2013; 88:157-63. [DOI: 10.1016/j.ijpsycho.2013.03.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 01/10/2013] [Accepted: 03/19/2013] [Indexed: 01/20/2023]
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21
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Paulus MP. The breathing conundrum-interoceptive sensitivity and anxiety. Depress Anxiety 2013; 30:315-20. [PMID: 23468141 PMCID: PMC3805119 DOI: 10.1002/da.22076] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 01/17/2013] [Accepted: 01/18/2013] [Indexed: 01/11/2023] Open
Abstract
Cognitive and affective processing has been the central focus of brain-related functions in psychology and psychiatry for many years. Much less attention has been paid to what could be considered the primary function of the brain, to regulate the function of the body. Recent developments, which include the conceptualization of interoception as a process consisting of integrating the information coming from the inside of the body in the central nervous system and the appreciation that complex emotional processes are fundamentally affected by the processing and regulation of somatic states, have profoundly changed the view of the function and dysfunction of the brain. This review focuses on the relationship between breathing and anxiety. Several anxiety disorders have been associated with altered breathing, perception of breathing, and response to manipulations of breathing. Both clinical and experimental research studies are reviewed that relate breathing dysfunctions to anxiety. Altered breathing may be useful as a physiological marker of anxiety as well as a treatment target using interoceptive interventions.
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Affiliation(s)
- Martin P. Paulus
- University of California, San Diego
,San Diego Veterans Affairs Health Care System
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