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Bryant RA, Dawson KS, Azevedo S, Yadav S, Cahill C, Kenny L, Maccallum F, Tran J, Rawson N, Tockar J, Garber B, Keyan D. A pilot study of the role of the BDNF Val66Met polymorphism in response to exercise-augmented exposure therapy for posttraumatic stress disorder. Psychoneuroendocrinology 2024; 167:107106. [PMID: 38943720 DOI: 10.1016/j.psyneuen.2024.107106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 06/16/2024] [Accepted: 06/17/2024] [Indexed: 07/01/2024]
Abstract
Brain-Derived Neurotrophic Factor (BDNF) is implicated in extinction learning, which is a primary mechanism of exposure therapy for posttraumatic stress disorder (PTSD). Brief aerobic exercise has been shown to promote BDNF release and augment extinction learning. On the premise that the Val allele of the BDNF Val66Met polymorphism facilitates greater release of BDNF, this study examined the extent to which the Val allele of the BDNF polymorphism predicted treatment response in PTSD patients who underwent exposure therapy combined with aerobic exercise or passive stretching. PTSD patients (N = 85) provided saliva samples in order to extract genomic DNA to identify Val/Val and Met carriers of the BDNF Val66Met genotype, and were assessed for PTSD severity prior to and following a 9-week course of exposure therapy combined with aerobic exercise or stretching. The sample comprised 52 Val/Val carriers and 33 Met carriers. Patients with the BDNF high-expression Val allele display greater reduction of PTSD symptoms at posttreatment than Met carriers. Hierarchical regression analysis indicated that greater PTSD reduction was specifically observed in Val/Val carriers who received exposure therapy in combination with the aerobic exercise. This finding accords with animal and human evidence that the BDNF Val allele promotes greater extinction learning, and that these individuals may benefit more from exercise-augmented extinction. Although preliminary, this result represents a possible avenue for augmented exposure therapy in patients with the BDNF Val allele.
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Affiliation(s)
- Richard A Bryant
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia; Brain Dynamics Centre, Westmead Institute for Medical Research, Sydney, New South Wales, Australia.
| | - Katie S Dawson
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Suzanna Azevedo
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Srishti Yadav
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Catherine Cahill
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Lucy Kenny
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Fiona Maccallum
- School of Psychology, University of Queensland, Brisbane, Queensland, Australia
| | - Jenny Tran
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Natasha Rawson
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Julia Tockar
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Benjamin Garber
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - Dharani Keyan
- School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
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Azar A, Hubert T, Adams TG, Cisler JM, Crombie KM. Exercise and Fear and Safety Learning. Curr Top Behav Neurosci 2024. [PMID: 39039358 DOI: 10.1007/7854_2024_494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Fear conditioning paradigms have been studied for over 100 years and are of great interest to the behavioral and clinical sciences given that several safety learning processes (e.g., extinction learning and recall) are thought to be fundamental to the success of exposure-based therapies for anxiety and related disorders. This chapter provides an overview of preclinical and clinical investigations that examined the effects of exercise on initial fear acquisition, fear extinction learning and consolidation, and return of fear outcomes. This chapter highlights the collective body of evidence suggesting that exercise administered after extinction learning enhances the consolidation and subsequent recall of extinction memories to a greater extent than exercise administered prior to extinction learning. This suggests that the addition of exercise after exposure therapy sessions may improve treatment outcomes for people with anxiety and related disorders. Potential mechanisms are discussed in addition to suggestions for future research to improve our understanding of the effects of exercise on fear conditioning and extinction outcomes.
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Affiliation(s)
- Ameera Azar
- Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Troy Hubert
- Department of Psychology, University of Kentucky, Lexington, KY, UK
| | - Thomas G Adams
- Department of Psychology, University of Kentucky, Lexington, KY, UK
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Josh M Cisler
- Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA
- Institute for Early Life Adversity Research, The University of Texas at Austin Dell Medical School, Austin, TX, USA
| | - Kevin M Crombie
- Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA.
- Department of Kinesiology, The University of Alabama, Tuscaloosa, AL, USA.
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3
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Tanner MK, Hohorst AA, Westerman JD, Mendoza CS, Han R, Moya NA, Jaime J, Alvarez LM, Dryden MQ, Balolia A, Abdul RA, Loetz EC, Greenwood BN. Pharmacological manipulations of the dorsomedial and dorsolateral striatum during fear extinction reveal opposing roles in fear renewal. Neurobiol Learn Mem 2024; 212:107937. [PMID: 38735637 PMCID: PMC11187715 DOI: 10.1016/j.nlm.2024.107937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/17/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024]
Abstract
Systemic manipulations that enhance dopamine (DA) transmission around the time of fear extinction can strengthen fear extinction and reduce conditioned fear relapse. Prior studies investigating the brain regions where DA augments fear extinction focus on targets of mesolimbic and mesocortical DA systems originating in the ventral tegmental area, given the role of these DA neurons in prediction error. The dorsal striatum (DS), a primary target of the nigrostriatal DA system originating in the substantia nigra (SN), is implicated in behaviors beyond its canonical role in movement, such as reward and punishment, goal-directed action, and stimulus-response associations, but whether DS DA contributes to fear extinction is unknown. We have observed that chemogenetic stimulation of SN DA neurons during fear extinction prevents the return of fear in contexts different from the extinction context, a form of relapse called renewal. This effect of SN DA stimulation is mimicked by a DA D1 receptor (D1R) agonist injected into the DS, thus implicating DS DA in fear extinction. Different DS subregions subserve unique functions of the DS, but it is unclear where in the DS D1R agonist acts during fear extinction to reduce renewal. Furthermore, although fear extinction increases neural activity in DS subregions, whether neural activity in DS subregions is causally involved in fear extinction is unknown. To explore the role of DS subregions in fear extinction, adult, male Long-Evans rats received microinjections of either the D1R agonist SKF38393 or a cocktail consisting of GABAA/GABAB receptor agonists muscimol/baclofen selectively into either dorsomedial (DMS) or dorsolateral (DLS) DS subregions immediately prior to fear extinction, and extinction retention and renewal were subsequently assessed drug-free. While increasing D1R signaling in the DMS during fear extinction did not impact fear extinction retention or renewal, DMS inactivation reduced later renewal. In contrast, DLS inactivation had no effect on fear extinction retention or renewal but increasing D1R signaling in the DLS during extinction reduced fear renewal. These data suggest that DMS and DLS activity during fear extinction can have opposing effects on later fear renewal, with the DMS promoting renewal and the DLS opposing renewal. Mechanisms through which the DS could influence the contextual gating of fear extinction are discussed.
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Affiliation(s)
- Margaret K Tanner
- Department of Psychology, University of Colorado Denver, Denver, CO, USA
| | - Alyssa A Hohorst
- Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
| | | | | | - Rebecca Han
- Department of Psychology, University of Colorado Denver, Denver, CO, USA
| | - Nicolette A Moya
- Department of Neuroscience, Northwestern Feinberg School of Medicine, Chicago, IL, USA
| | - Jennifer Jaime
- The Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lareina M Alvarez
- Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
| | - Miles Q Dryden
- Department of Psychology, University of Colorado Denver, Denver, CO, USA
| | - Aleezah Balolia
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Denver, CO, USA
| | - Remla A Abdul
- Department of Psychology, University of Colorado Denver, Denver, CO, USA
| | - Esteban C Loetz
- Department of Psychology, University of Colorado Denver, Denver, CO, USA
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Wang Y, Olsson S, Lipp OV, Ney LJ. Renewal in human fear conditioning: A systematic review and meta-analysis. Neurosci Biobehav Rev 2024; 159:105606. [PMID: 38431150 DOI: 10.1016/j.neubiorev.2024.105606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 02/13/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
Renewal is a 'return of fear' manipulation in human fear conditioning to investigate learning processes underlying anxiety and trauma. Even though renewal paradigms are widely used, no study has compared the strength of different renewal paradigms. We conduct a systematic review (N = 80) and meta-analysis (N = 23) of human fear conditioning studies assessing renewal. Our analysis shows that the classic ABA design is the most effective paradigm, compared to ABC and ABBA designs. We present evidence that conducting extinction in multiple contexts and increasing the similarity between acquisition and extinction contexts reduce renewal. Furthermore, we show that additional cues can be used as safety and 'protection from extinction' cues. The review shows that alcohol weakens the extinction process and that older adults appear less sensitive to context changes and thus show less renewal. The large variability in approaches to study renewal in humans suggests that standardisation of fear conditioning procedures across laboratories would be of great benefit to the field.
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Affiliation(s)
- Yi Wang
- School of Psychology and Counselling, Queensland University of Technology, Australia.
| | - Sarah Olsson
- School of Psychology and Counselling, Queensland University of Technology, Australia
| | - Ottmar V Lipp
- School of Psychology and Counselling, Queensland University of Technology, Australia
| | - Luke J Ney
- School of Psychology and Counselling, Queensland University of Technology, Australia
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Cisler JM, Dunsmoor JE, Privratsky AA, James GA. Decoding neural reactivation of threat during fear learning, extinction, and recall in a randomized clinical trial of L-DOPA among women with PTSD. Psychol Med 2024; 54:1091-1101. [PMID: 37807886 DOI: 10.1017/s0033291723002891] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
BACKGROUND Laboratory paradigms are widely used to study fear learning in posttraumatic stress disorder (PTSD). Recent basic science models demonstrate that, during fear learning, patterns of activity in large neuronal ensembles for the conditioned stimuli (CS) begin to reinstate neural activity patterns for the unconditioned stimuli (US), suggesting a direct way of quantifying fear memory strength for the CS. Here, we translate this concept to human neuroimaging and test the impact of post-learning dopaminergic neurotransmission on fear memory strength during fear acquisition, extinction, and recall among women with PTSD in a re-analysis of previously reported data. METHODS Participants (N = 79) completed a context-dependent fear acquisition and extinction task on day 1 and extinction recall tests 24 h later. We decoded activity patterns in large-scale functional networks for the US, then applied this decoder to activity patterns toward the CS on day 1 and day 2. RESULTS US decoder output for the CS+ increased during acquisition and decreased during extinction in networks traditionally implicated in human fear learning. The strength of US neural reactivation also predicted individuals skin conductance responses. Participants randomized to receive L-DOPA (n = 43) following extinction on day 1 demonstrated less US neural reactivation on day 2 relative to the placebo group (n = 28). CONCLUSION These results support neural reactivation as a measure of memory strength between competing memories of threat and safety and further demonstrate the role of dopaminergic neurotransmission in the consolidation of fear extinction memories.
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Affiliation(s)
- Josh M Cisler
- Department of Psychiatry and Behavioral Sciences, Dell Medical School, University of Texas at Austin, Austin, TX, USA
- Institute for Early Life Adversity Research, Dell Medical School, University of Texas at Austin, Austin, TX, USA
| | - Joseph E Dunsmoor
- Department of Psychiatry and Behavioral Sciences, Dell Medical School, University of Texas at Austin, Austin, TX, USA
- Institute for Early Life Adversity Research, Dell Medical School, University of Texas at Austin, Austin, TX, USA
| | | | - G Andrew James
- Brain Imaging Research Center, Department of Psychiatry, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Pebole MM, Singleton CR, Hall KS, Petruzzello SJ, Reginald A, Smith BN, Whitworth JW, Gobin RL. Sex-specific associations between self-reported physical activity and PTSD among survivors of sexual violence. J Behav Med 2024; 47:220-231. [PMID: 37698803 DOI: 10.1007/s10865-023-00434-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 06/28/2023] [Indexed: 09/13/2023]
Abstract
This study examined sex-specific associations between sexual violence (SV) type and physical activity, and identified associations between PTSD symptoms and physical activity, all among cisgender men and women survivors of SV. Cross-sectional data from men (n = 197) and women (n = 356) survivors of SV were analyzed with stratified (men; women) hierarchical logistic regressions. Additionally, fully adjusted models for the total sample included interaction terms to further assess whether associations between SV type as well as PTSD symptoms (sum, clusters) and physical activity differed significantly by sex. Sexual assault was negatively associated with physical activity in the crude model among women (ORs: 0.58; p < 0.05). Harassment was positively associated with physical activity in the crude and adjusted models (ORs:1.92-2.16; ps<0.05) among women. Among men, there were no significant relationships. Regarding PTSD symptoms among women, crude and adjusted stratified models identified significant positive relationships with intrusion (ORs: 1.18-1.22; ps<0.05). Crude and adjusted models revealed significant positive relationships between avoidance and activity (ORs:1.38-1.41; ps<0.05) among men but not women. The interaction term for this difference in the association between avoidance and physical activity by sex was significant (OR: 0.65; 95%CI: 0.48-0.88; p < 0.01). Overall, findings provide evidence for sex-specific associations between SV and physical activity.
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Affiliation(s)
- Michelle M Pebole
- The Translational Research Center for TBI and Stress Disorders (TRACTS), Veterans Affairs Boston Healthcare System, 150 S Huntington Ave, Boston, MA, 02130, USA.
- Department of Kinesiology and Community Health, University of Illinois at Urbana Champaign, 505 E Armory Ave, Champaign, IL, 61280, USA.
| | - Chelsea R Singleton
- Department of Social, Behavioral, and Population Sciences, Tulane School of Public Health & Tropical Medicine, 1440 Canal Street, New Orleans, LA, 70112, USA
| | - Katherine S Hall
- Geriatric Research, Education, and Clinical Center, Durham VA Healthcare System, 508 Fulton St, Durham, NC, 27705, USA
- Department of Medicine, Duke University, 2301 Erwin Road, Durham, NC, 27710, USA
| | - Steven J Petruzzello
- Department of Kinesiology and Community Health, University of Illinois at Urbana Champaign, 505 E Armory Ave, Champaign, IL, 61280, USA
| | - Alston Reginald
- Department of Kinesiology and Community Health, University of Illinois at Urbana Champaign, 505 E Armory Ave, Champaign, IL, 61280, USA
| | - Brian N Smith
- National Center for PTSD Women's Health Sciences Division, VA Boston Healthcare System, 150 S Huntington Ave, Boston, MA, 02130, USA
- Department of Psychiatry, Boston University Chobanian & Avedisian School of Medicine, 720 Harrison Avenue, Boston, MA, 02118, USA
| | - James W Whitworth
- National Center for PTSD Behavioral Science Division at VA Boston Healthcare System, 150 S Huntington Ave, Boston, MA, 02130, USA
- Department of Psychiatry, Boston University Chobanian & Avedisian School of Medicine, 720 Harrison Avenue, Boston, MA, 02118, USA
| | - Robyn L Gobin
- Department of Kinesiology and Community Health, University of Illinois at Urbana Champaign, 505 E Armory Ave, Champaign, IL, 61280, USA
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Rahimi-Danesh M, Samizadeh MA, Sajadi AE, Rezvankhah T, Vaseghi S. Sex difference affects fear extinction but not lithium efficacy in rats following fear-conditioning with respect to the hippocampal level of BDNF. Pharmacol Biochem Behav 2024; 234:173675. [PMID: 37972713 DOI: 10.1016/j.pbb.2023.173675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/19/2023]
Abstract
In rodents, exposure to electrical shock and creating a strong fear memory using fear-conditioning model can induce PTSD-like behavior. In this study, we induced a fear-conditioning model in rats and investigated freezing (PTSD-like) behavior, 21 days after three shocks exposure (0.6 mA, 3 s, 30 seconds interval) in both male and female rats. Lithium was injected intraperitoneally (100 mg/kg) in three protocols: (1) 1 h after fear-conditioning (2) 1 h, 24 h, and 48 h after fear-conditioning (3), 1 h, 24 h, 48 h, 72 h, and 96 h after fear-conditioning. Extinction training (20 sounds without shocks, 75 dB, 3 s, 30 seconds interval) was performed in three protocols: (1) 1 h after fear-conditioning (one session), (2) 1 h, 24 h, and 48 h after fear-conditioning (three sessions), (3), 1 h, 24 h, 48 h, 72 h, and 96 h after fear-conditioning (five sessions). Forced swim test (FST) and hot plate were used to assess behavior. Results showed that lithium in all protocols had no effect on freezing behavior, FST, and pain subthreshold in all rats. Extinction training decreased freezing behavior, with more efficacy in females. In males, only 5-session training was effective, while in females all protocols were effective. Extinction training also altered pain perception and the results of FST, depending on the sessions and was different in males and females. Brain-derived neurotrophic factor (BDNF) mRNA level was increased in females following 3 and 5 sessions, and in males following 5 sessions extinction training. In conclusion, we suggested that there is a sex difference for the effect of extinction training on freezing behavior and BDNF mRNA level in a rat model of fear-conditioning.
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Affiliation(s)
- Mehrsa Rahimi-Danesh
- Cognitive Neuroscience Lab, Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran
| | - Mohammad-Ali Samizadeh
- Cognitive Neuroscience Lab, Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran
| | - Amir-Ehsan Sajadi
- Cognitive Neuroscience Lab, Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran
| | - Tara Rezvankhah
- Cognitive Neuroscience Lab, Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran
| | - Salar Vaseghi
- Cognitive Neuroscience Lab, Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran; Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran.
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8
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Bustamante J, Soto M, Miguez G, Quezada-Scholz VE, Angulo R, Laborda MA. Extinction in multiple contexts reduces the return of extinguished responses: A multilevel meta-analysis. Learn Behav 2023:10.3758/s13420-023-00609-w. [PMID: 38010486 DOI: 10.3758/s13420-023-00609-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2023] [Indexed: 11/29/2023]
Abstract
Extinguished responses have been shown to reappear under several circumstances, and this reappearance is considered to model behaviors such as relapse after exposure therapy. Conducting extinction in multiple contexts has been explored as a technique to decrease the recovery of extinguished responses. The present meta-analysis aimed to examine whether extinction in multiple contexts can consistently reduce the recovery of extinguished responses. After searching in several databases, experiments were included in the analysis if they presented extinction in multiple contexts, an experimental design, and an adequate statistical report. Cohen's d was obtained for each critical comparison and weighted to obtain the sample's average weighted effect size. Analyses were then performed using a multilevel meta-analytic approach. Twenty-five studies were included, with a total sample of 37 experiments or critical comparisons. The analyses showed a large effect size for the sample, moderated by the length of conditioned stimulus exposure, type of experimental subject, and type of recovery. The robust effect of extinction in multiple contexts on relapse should encourage clinicians to consider extinction in multiple contexts as a useful technique in therapy and research.
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Affiliation(s)
- Javier Bustamante
- Institute of Social Sciences, Universidad de O'Higgins, Av. Libertador Bernardo O'Higgins 611, Rancagua, Chile
| | - Marcela Soto
- School of Psychology, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
| | - Gonzalo Miguez
- Department of Psychology, Universidad de Chile, Av. Ignacio Carrera Pinto 1045, Ñuñoa, 7800284, Santiago, Chile
| | - Vanetza E Quezada-Scholz
- Department of Psychology, Universidad de Chile, Av. Ignacio Carrera Pinto 1045, Ñuñoa, 7800284, Santiago, Chile
| | - Rocío Angulo
- Institute of Social Sciences, Universidad de O'Higgins, Av. Libertador Bernardo O'Higgins 611, Rancagua, Chile
| | - Mario A Laborda
- Department of Psychology, Universidad de Chile, Av. Ignacio Carrera Pinto 1045, Ñuñoa, 7800284, Santiago, Chile.
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Jentsch VL, Wolf OT, Otto T, Merz CJ. The impact of physical exercise on the consolidation of fear extinction memories. Psychophysiology 2023; 60:e14373. [PMID: 37350416 DOI: 10.1111/psyp.14373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/11/2023] [Accepted: 06/05/2023] [Indexed: 06/24/2023]
Abstract
Based on the mechanisms of fear extinction, exposure therapy is the most common treatment for anxiety disorders. However, extinguished fear responses can reemerge even after successful treatment. Novel interventions enhancing exposure therapy efficacy are therefore critically needed. Physical exercise improves learning and memory and was also shown to enhance extinction processes. This study tested whether physical exercise following fear extinction training improves the consolidation of extinction memories. Sixty healthy men underwent a differential fearconditioning paradigm with fear acquisition training on day 1 and fear extinction training followed by an exercise or resting control intervention on day 2. On day 3, retrieval and reinstatement were tested including two additional but perceptually similar stimuli to explore the generalization of exercise effects. Exercise significantly increased heart rate, salivary alpha amylase, and cortisol, indicating successful exercise manipulation. Contrary to our expectations, exercise did not enhance but rather impaired extinction memory retrieval on the next day, evidenced by significantly stronger differential skin conductance responses (SCRs) and pupil dilation (PD). Importantly, although conditioned fear responses were successfully acquired, they did not fully extinguish, explaining why exercise might have boosted the consolidation of the original fear memory trace instead. Additionally, stronger differential SCRs and PD toward the novel stimuli suggest that the memory enhancing effects of exercise also generalized to perceptually similar stimuli. Together, these findings indicate that physical exercise can facilitate both the long-term retrievability and generalization of extinction memories, but presumably only when extinction was successful in the first place.
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Affiliation(s)
- Valerie L Jentsch
- Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
| | - Oliver T Wolf
- Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
| | - Tobias Otto
- Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
| | - Christian J Merz
- Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
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10
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Adams TG, Kelmendi B, George JR, Forte J, Hubert TJJ, Wild H, Rippey CS, Pittenger C. Frontopolar multifocal transcranial direct current stimulation reduces conditioned fear reactivity during extinction training: A pilot randomized controlled trial. Neurobiol Learn Mem 2023; 205:107825. [PMID: 37699439 PMCID: PMC10872945 DOI: 10.1016/j.nlm.2023.107825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 08/16/2023] [Accepted: 09/03/2023] [Indexed: 09/14/2023]
Abstract
Exposure-based therapies for anxiety and related disorders are believed to depend on fear extinction learning and corresponding changes in extinction circuitry. Frontopolar multifocal transcranial direct current stimulation (tDCS) has been shown to improve therapeutic safety learning during in vivo exposure and may modulate functional connectivity of networks implicated in fear processing and inhibition. A pilot randomized controlled trial was completed to determine the effects of frontopolar tDCS on extinction learning and memory. Community volunteers (n = 35) completed a 3-day fear extinction paradigm with measurement of electrodermal activity. Participants were randomized (single-blind) to 20-min of sham (n = 17, 30 s. ramp in/out) or active (n = 18) frontopolar (anode over Fpz, 10-10 EEG) multifocal tDCS (20-min, 1.5 mA) prior to extinction training. Mixed ANOVAs revealed a significant group*trial effect on skin conductance response (SCR) to the conditioned stimulus (CS + ) during extinction training (p = 0.007, Cohen's d = 0.55). The effects of frontopolar tDCS were greatest during the first two extinction trials, suggesting that tDCS may have promoted fear inhibition prior to safety learning. Return of fear to the CS + during tests were comparable across conditions (ps > 0.50). These findings suggest that frontopolar tDCS may modulate the processing of threat cues and associated circuitry or promote the inhibition of fear. This has clear implications for the treatment of anxiety and related disorders with therapeutic exposure.
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Affiliation(s)
- Thomas G Adams
- Department of Psychology, University of Kentucky, United States; Department of Psychiatry, Yale University School of Medicine, United States.
| | - Benjamin Kelmendi
- Department of Psychiatry, Yale University School of Medicine, United States; Clinical Neuroscience Division of the National Center for PTSD, West Haven VA Medical Center, United States
| | - Jamilah R George
- Department of Psychiatry, Yale University School of Medicine, United States; Department of Psychological Sciences, University of Connecticut, United States
| | - Jennifer Forte
- Department of Psychiatry, Yale University School of Medicine, United States; Department of Psychology, Binghamton University, United States
| | - Troy J J Hubert
- Department of Psychology, University of Kentucky, United States
| | - Hannah Wild
- Department of Psychology, University of Kentucky, United States
| | - Colton S Rippey
- Department of Psychology, University of Kentucky, United States
| | - Christopher Pittenger
- Department of Psychiatry, Yale University School of Medicine, United States; Child Study Center, Yale University, United States; Department of Psychology, Center for Brain and Mind Health, Yale University, United States
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11
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Crombie KM, Azar A, Botsford C, Heilicher M, Hiser J, Moughrabi N, Gruichich TS, Schomaker CM, Cisler JM. The influence of aerobic exercise on model-based decision making in women with posttraumatic stress disorder. JOURNAL OF MOOD AND ANXIETY DISORDERS 2023; 2:100015. [PMID: 37593142 PMCID: PMC10433398 DOI: 10.1016/j.xjmad.2023.100015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Individuals with PTSD often exhibit deficits in executive functioning. An unexplored aspect of neurocognitive functions associated with PTSD is the type of learning system engaged in during decision-making. A model-free (MF) system is habitual in nature and involves trial-and-error learning that is often updated based on the most recent experience (e.g., repeat action if rewarded). A model-based (MB) system is goal-directed in nature and involves the development of an abstract representation of the environment to facilitate decisions (e.g., choose sequence of actions according to current contextual state and predicted outcomes). The existing neurocognitive literature on PTSD suggests the hypothesis of greater reliance on MF vs MB learning strategies when navigating their environment. While MF systems may be more cognitively efficient, they do not afford flexibility when making prospective predictions about likely outcomes of different decision-tree branches. Emerging research suggests that an acute bout of aerobic exercise improves certain aspects of neurocognition, and thereby could promote the utilization of MB over MF systems during decision making, although prior research has not yet tested this hypothesis. Accordingly, the current study administered a lab-based two-stage Markov decision-making task capable of discriminating MF vs MB decision making, in order to determine if moderate-intensity aerobic exercise (either shortly after or 30-minutes after the exercise bout has ended) promotes greater engagement in MB behavioral strategies compared to light-intensity aerobic exercise in adult women with and without PTSD (N=61). Results revealed that control women generally displayed higher levels of MB behavior that was further increased following immediate exercise, particularly moderate-intensity exercise. By contrast, the PTSD group generally displayed lower levels of MB behavior, and exhibited greater MB behavior when completing the task following moderate-intensity aerobic exercise compared to light-intensity aerobic exercise regardless of whether there was a short or long delay between exercise and the task. Additionally, women with PTSD demonstrated less impairment in MB decision-making compared to controls following moderate-intensity aerobic exercise. These results suggest that an acute bout of moderate-intensity aerobic exercise boosts MB behavior in women with PTSD, and suggests that aerobic exercise may play an important role in enhancing cognitive outcomes for PTSD.
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Affiliation(s)
- Kevin M. Crombie
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
- The University of Alabama, Department of Kinesiology, 1003 Wade Hall, Tuscaloosa, Alabama, United States of America 35487
| | - Ameera Azar
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Chloe Botsford
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America 53719
| | - Mickela Heilicher
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America 53719
| | - Jaryd Hiser
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America 53719
- The Ohio State University, Department of Psychiatry and Behavioral Health, 1670 Upham Drive, Suite 130, Columbus, Ohio, United States of America 43210
| | - Nicole Moughrabi
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Tijana Sagorac Gruichich
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America 53719
| | - Chloe M. Schomaker
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Josh M. Cisler
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
- Institute for Early Life Adversity Research, The University of Texas at Austin Dell Medical School, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
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Crombie KM, Azar A, Botsford C, Heilicher M, Moughrabi N, Gruichich TS, Schomaker CM, Dunsmoor JE, Cisler JM. Aerobic exercise after extinction learning reduces return of fear and enhances memory of items encoded during extinction learning. Ment Health Phys Act 2023; 24:100510. [PMID: 37065640 PMCID: PMC10104454 DOI: 10.1016/j.mhpa.2023.100510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Fear conditioning paradigms are widely used in laboratory settings to discover treatments that enhance memory consolidation and various fear processes (extinction learning, limit return of fear) that are relevant targets of exposure-based therapies. However, traditional lab-based paradigms often use the exact same conditioned stimuli for acquisition and extinction (typically differentiated with a context manipulation), whereas the opposite is true in clinical settings, as exposure therapy rarely (if ever) uses precisely the exact same stimuli from an individual's learning history. Accordingly, this study utilized a novel three-day category-based fear conditioning protocol (that uses categories of non-repeating objects [animals and tools] as conditioned stimuli during fear conditioning and extinction) to determine if aerobic exercise enhances the consolidation of extinction learning (reduces return of fear) and memory (for items encoded during extinction) during subsequent tests of extinction recall. Participants (n=40) completed a fear acquisition (day 1), fear extinction (day 2), and extinction recall (day 3) protocol. On day 1, participants completed a fear acquisition task in which they were trained to associate a category of conditioned stimuli (CS+) with the occurrence of an unconditioned stimulus (US). On day 2, participants were administered a fear extinction procedure during which CS+ and CS- categorical stimuli were presented in absence of the occurrence of the US. After completing the task, participants were randomly assigned to either receive moderate-intensity aerobic exercise (EX) or a light-intensity control (CON) condition. On day 3, participants completed fear recall tests (during which day 1, day 2, and novel CS+ and CS- stimuli were presented). Fear responding was assessed via threat expectancy ratings and skin conductance responses (SCR). During the fear recall tests, the EX group reported significantly lower threat expectancy ratings to the CS+ and CS- and exhibited greater memory of CS+ and CS- stimuli that were previously presented during day 2. There were no significant group differences for SCR. These results suggests that administration of moderate-intensity aerobic exercise following extinction learning contributes to reduced threat expectancies during tests of fear recall and enhanced memory of items encoded during extinction.
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Affiliation(s)
- Kevin M. Crombie
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Ameera Azar
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Chloe Botsford
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America, 53719
| | - Mickela Heilicher
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America, 53719
| | - Nicole Moughrabi
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Tijana Sagorac Gruichich
- University of Wisconsin – Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, Wisconsin, United States of America, 53719
| | - Chloe M. Schomaker
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Joseph E. Dunsmoor
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
| | - Josh M. Cisler
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
- Institute for Early Life Adversity Research, The University of Texas at Austin Dell Medical School, 1601 Trinity Street, Building B, Austin, Texas, United States of America 78712
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Crombie KM, Adams TG, Dunsmoor JE, Greenwood BN, Smits JA, Nemeroff CB, Cisler JM. Aerobic exercise in the treatment of PTSD: An examination of preclinical and clinical laboratory findings, potential mechanisms, clinical implications, and future directions. J Anxiety Disord 2023; 94:102680. [PMID: 36773486 PMCID: PMC10084922 DOI: 10.1016/j.janxdis.2023.102680] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/19/2023] [Accepted: 02/03/2023] [Indexed: 02/09/2023]
Abstract
Posttraumatic stress disorder (PTSD) is associated with heightened emotional responding, avoidance of trauma related stimuli, and physical health concerns (e.g., metabolic syndrome, type 2 diabetes, cardiovascular disease). Existing treatments such as exposure-based therapies (e.g., prolonged exposure) aim to reduce anxiety symptoms triggered by trauma reminders, and are hypothesized to work via mechanisms of extinction learning. However, these conventional gold standard psychotherapies do not address physical health concerns frequently presented in PTSD. In addition to widely documented physical and mental health benefits of exercise, emerging preclinical and clinical evidence supports the hypothesis that precisely timed administration of aerobic exercise can enhance the consolidation and subsequent recall of fear extinction learning. These findings suggest that aerobic exercise may be a promising adjunctive strategy for simultaneously improving physical health while enhancing the effects of exposure therapies, which is desirable given the suboptimal efficacy and remission rates. Accordingly, this review 1) encompasses an overview of preclinical and clinical exercise and fear conditioning studies which form the basis for this claim; 2) discusses several plausible mechanisms for enhanced consolidation of fear extinction memories following exercise, and 3) provides suggestions for future research that could advance the understanding of the potential importance of incorporating exercise into the treatment of PTSD.
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Affiliation(s)
- Kevin M Crombie
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States of America.
| | - Tom G Adams
- University of Kentucky, Department of Psychology, 105 Kastle Hill, Lexington, KY 40506-0044, United States of America; Yale School of Medicine, Department of Psychiatry, 300 George St., New Haven, CT 06511, United States of America
| | - Joseph E Dunsmoor
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States of America
| | - Benjamin N Greenwood
- University of Colorado Denver, Department of Psychology, Campus Box 173, PO Box 173364, Denver, CO 80217-3364, United States of America
| | - Jasper A Smits
- The University of Texas at Austin, Department of Psychology, 108 E Dean Keeton St., Austin, TX 78712, United States of America
| | - Charles B Nemeroff
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States of America; Institute for Early Life Adversity Research, The University of Texas at Austin Dell Medical School, 1601 Trinity Street, Building B, Austin, TX 78712, United States of America
| | - Josh M Cisler
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States of America; Institute for Early Life Adversity Research, The University of Texas at Austin Dell Medical School, 1601 Trinity Street, Building B, Austin, TX 78712, United States of America
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Provencher J, Cernik R, Marin MF. Impact of Stress and Exercise on Fear Extinction. Curr Top Behav Neurosci 2023; 64:157-178. [PMID: 37498495 DOI: 10.1007/7854_2023_432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
This chapter reviews the literature on the impact of stress and exercise on fear extinction. Given that key brain regions of the fear circuitry (e.g., hippocampus, amygdala and frontal cortex) can be modulated by stress hormones, it is important to investigate how stress influences this process. Laboratory-based studies performed in healthy adults have yielded mixed results, which are most likely attributable to various methodological factors. Among these factors, inter-individual differences modulating the stress response and timing of stressor administration with respect to the task may contribute to this heterogeneity. Given that fear is a core manifestation of various psychopathologies and that exposure-based therapy relies on fear extinction principles, several studies have attempted to assess the role of stress hormones on exposure-based therapy in patients suffering from post-traumatic stress disorder or anxiety disorders. These studies tend to suggest a beneficial impact of stress hormones (through either natural endogenous variations or synthetic administration) on exposure-based therapy as assessed mostly by subjective fear measures. Similar to stress, exercise can have an impact on many physiological and biological systems in humans. Of note, exercise modulates biomarkers such as brain-derived neurotrophic factor (BDNF) and anandamide (EAE) that act on brain regions implicated in the fear circuitry, supporting the importance of studying the impact of exercise on fear extinction. Overall, the results converge and indicate that fear extinction (tested in the laboratory or via exposure-based therapy in clinical populations) can be enhanced with exercise. Further research is needed to understand the mechanisms by which stress and exercise modulate fear learning and extinction processes, as well as to maximize the applicability to clinical contexts.
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Affiliation(s)
- Jessie Provencher
- Department of Psychology, Université du Québec à Montréal, Montreal, QC, Canada
- Research Centre of the Institut Universitaire en Santé Mentale de Montréal, Montreal, QC, Canada
| | - Rebecca Cernik
- Department of Psychology, Université du Québec à Montréal, Montreal, QC, Canada
- Research Centre of the Institut Universitaire en Santé Mentale de Montréal, Montreal, QC, Canada
| | - Marie-France Marin
- Department of Psychology, Université du Québec à Montréal, Montreal, QC, Canada.
- Research Centre of the Institut Universitaire en Santé Mentale de Montréal, Montreal, QC, Canada.
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Botsford C, Brellenthin AG, Cisler JM, Hillard CJ, Koltyn KF, Crombie KM. Circulating endocannabinoids and psychological outcomes in women with PTSD. J Anxiety Disord 2023; 93:102656. [PMID: 36469982 PMCID: PMC9839585 DOI: 10.1016/j.janxdis.2022.102656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 10/10/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND Recent research has attempted to elucidate the relationship between blood-based biomarkers (e.g., endocannabinoids; eCBs: including N-arachidonoylethanolamine [AEA] and 2-arachidonoylglycerol [2-AG]) and mental health outcomes in psychiatric populations such as posttraumatic stress disorder (PTSD). Prior research suggests that adults with PTSD may have altered circulating eCB tone and a blunted mobilization of eCBs (particularly 2-AG) in response to stress (e.g., aerobic exercise), although our understanding has been limited in part due to heterogenous samples and small sample sizes. METHODS A subset of data was pooled from five studies in which women with and without PTSD (N = 98) completed questionnaires related to mood states and a blood draw prior to and following a bout of moderate-intensity aerobic exercise in order to determine: 1) whether circulating eCBs differ between groups and whether depressive and PTSD symptom severity are associated with baseline eCBs, 2) whether a bout of aerobic exercise increases circulating eCBs in adult women with PTSD, and 3) whether circulating eCBs are associated with overall mood states and exercise-induced improvements in mood states in women with and without PTSD. RESULTS PTSD diagnoses were not associated with baseline concentrations of eCBs. Greater depressive symptom severity and PTSD symptom severity within the negative alteration in cognition and mood cluster were associated with lower circulating AEA. Circulating AEA significantly increased following aerobic exercise for both groups, whereas circulating 2-AG only increased in women without PTSD. Greater circulating AEA within the PTSD group was associated with lower depressive mood, confusion, and total mood disturbance. CONCLUSIONS These findings suggest that greater circulating AEA is associated with better overall mood and lower depressive and PTSD symptom severity, and that an acute bout of moderate-intensity aerobic exercise increases circulating AEA (but not 2-AG) in adult women with PTSD. These findings are consistent with the idea that greater eCB tone (particularly AEA) following pharmacological and/or non-pharmacological manipulations may be beneficial for improving psychological outcomes (e.g., mood, cognition) among PTSD, and possibly other psychiatric populations.
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Affiliation(s)
- Chloe Botsford
- University of Wisconsin - Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, WI 53719, United States.
| | - Angelique G Brellenthin
- Iowa State University, Department of Kinesiology, Forker Building, 534 Wallace Road, Ames, IA 50011, United States.
| | - Josh M Cisler
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States; Institute for Early Life Adversity Research, The University of Texas at Austin Dell Medical School & Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States.
| | - Cecilia J Hillard
- Medical College of Wisconsin, Neuroscience Research Center, Department of Pharmacology and Toxicology, 8701 Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Kelli F Koltyn
- University of Wisconsin - Madison, Department of Kinesiology, 1300 University Avenue, Madison, WI 53706, United States.
| | - Kevin M Crombie
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, 1601 Trinity Street, Building B, Austin, TX 78712, United States.
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Desai S, Borg B, Cuttler C, Crombie KM, Rabinak CA, Hill MN, Marusak HA. A Systematic Review and Meta-Analysis on the Effects of Exercise on the Endocannabinoid System. Cannabis Cannabinoid Res 2022; 7:388-408. [PMID: 34870469 PMCID: PMC9418357 DOI: 10.1089/can.2021.0113] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Introduction: The endocannabinoid (eCB) system plays a key role in maintaining homeostasis, including the regulation of metabolism and stress responses. Chronic stress may blunt eCB signaling, and disruptions in eCB signaling have been linked to stress-related psychiatric disorders and physical health conditions, including anxiety, depression, post-traumatic stress disorder (PTSD), diabetes, and obesity. Pharmacological and nonpharmacological behavioral interventions (e.g., exercise) that target the eCB system may be promising therapeutic approaches for the prevention and treatment of stress-related diseases. In this study, we perform a systematic review and the first meta-analysis to examine the impact of exercise on circulating eCB concentrations. Materials and Methods: We performed a review of the MEDLINE (PubMed) database for original articles examining the impact of exercise on eCBs in humans and animal models. A total of 262 articles were screened for initial inclusion. Results: Thirty-three articles (reporting on 57 samples) were included in the systematic review and 10 were included in the meta-analysis. The majority of samples that measured anandamide (AEA) showed a significant increase in AEA concentrations following acute exercise (74.4%), whereas effects on 2-arachidonoylglycerol (2-AG) were inconsistent. The meta-analysis, however, revealed a consistent increase in both AEA and 2-AG following acute exercise across modalities (e.g., running, cycling), species (e.g., humans, mice), and in those with and without pre-existing health conditions (e.g., PTSD, depression). There was substantial heterogeneity in the magnitude of the effect across studies, which may relate to exercise intensity, physical fitness, timing of measurement, and/or fasted state. Effects of chronic exercise were inconsistent. Conclusions: Potential interpretations and implications of exercise-induced mobilization of eCBs are discussed, including refilling of energy stores and mediating analgesic and mood elevating effects of exercise. We also offer recommendations for future work and discuss therapeutic implications for exercise in the prevention and treatment of stress-related psychopathology.
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Affiliation(s)
- Shreya Desai
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Breanna Borg
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Carrie Cuttler
- Department of Psychology, Washington State University, Pullman, Washington, USA
| | - Kevin M. Crombie
- Department of Psychiatry and Behavioral Sciences, University of Texas at Austin, Austin, Texas, USA
| | - Christine A. Rabinak
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, Michigan, USA
- Department of Pharmacy Practice and Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
- Merrill Palmer Skillman Institute for Child and Family Development, Wayne State University, Detroit, Michigan, USA
| | - Matthew N. Hill
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hilary A. Marusak
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, Michigan, USA
- Merrill Palmer Skillman Institute for Child and Family Development, Wayne State University, Detroit, Michigan, USA
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Crombie KM, Privratsky AA, Schomaker CM, Heilicher M, Ross MC, Sartin-Tarm A, Sellnow K, Binder EB, Andrew James G, Cisler JM. The influence of FAAH genetic variation on physiological, cognitive, and neural signatures of fear acquisition and extinction learning in women with PTSD. Neuroimage Clin 2022; 33:102922. [PMID: 34952353 PMCID: PMC8715233 DOI: 10.1016/j.nicl.2021.102922] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 12/14/2022]
Abstract
PTSD is often treated with psychotherapies based on principles of fear acquisition and extinction. Increased AEA has resulted in enhanced extinction learning and recall among healthy adults. These effects have not yet been comprehensively examined in a PTSD population. Results suggest that genetic variation within the FAAH gene affects how fear learning is tuned in women with PTSD.
Background Posttraumatic Stress Disorder (PTSD) is commonly treated with exposure-based cognitive therapies that are based on the principles of fear acquisition and extinction learning. Elevations in one of the major endocannabinoids (anandamide) either via inhibition of the primary degrading enzyme (fatty acid amide hydrolase; FAAH) or via a genetic variation in the FAAH gene (C385A; rs324420) has resulted in accelerated extinction learning and enhanced extinction recall among healthy adults. These results suggest that targeting FAAH may be a promising therapeutic approach for PTSD. However, these effects have not yet been comprehensively examined in a PTSD population. Methods The current study examined whether genetic variation in the FAAH gene (CC [n = 49] vs AA/AC [n = 36] allele carriers) influences physiological (skin conductance), cognitive (threat expectancy), and neural (network and voxel-wise activation) indices of fear acquisition and extinction learning among a sample of adult women with PTSD (N = 85). Results The physiological, cognitive, and neural signatures of fear acquisition and extinction learning varied as a function of whether or not individuals possess the FAAH C385A polymorphism. For instance, we report divergent responding between CC and AA/AC allele carriers to CS + vs CS- in limbic and striatum networks and overall greater activation throughout the task among AA/AC allele carriers in several regions [e.g., inferior frontal, middle frontal, parietal] that are highly consistent with a frontoparietal network involved in higher-order executive functions. Conclusions These results suggest that genetic variation within the FAAH gene influences physiological, cognitive, and neural signatures of fear learning in women with PTSD. In order to advance our understanding of the efficacy of FAAH inhibition as a treatment for PTSD, future clinical trials in this area should assess genetic variation in the FAAH gene in order to fully depict and differentiate the acute effects of a drug manipulation (FAAH inhibition) from more chronic (genetic) influences on fear extinction processes.
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Affiliation(s)
- Kevin M Crombie
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, Health Discovery Building, 1601 Trinity St., Building B, Austin, TX 78712, USA.
| | - Anthony A Privratsky
- University of Arkansas for Medical Sciences, Brain Imaging Research Center, 4301 W. Markham Street #554, Little Rock, AR 72205, USA
| | - Chloe M Schomaker
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, Health Discovery Building, 1601 Trinity St., Building B, Austin, TX 78712, USA
| | - Mickela Heilicher
- University of Wisconsin - Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, WI 53719-1176608-262-6375, USA
| | - Marisa C Ross
- University of Wisconsin - Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, WI 53719-1176608-262-6375, USA
| | - Anneliis Sartin-Tarm
- University of Wisconsin - Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, WI 53719-1176608-262-6375, USA
| | - Kyrie Sellnow
- University of Wisconsin - Madison, Department of Psychiatry, 6001 Research Park Boulevard, Madison, WI 53719-1176608-262-6375, USA
| | - Elisabeth B Binder
- Max Planck Institute of Psychiatry, Department of Translational Psychiatry, Kraepelinstr. 2-10, 80804, Munchen, Germany; Emory University, Department of Psychiatry and Behavioral Sciences, 12 Executive Park Dr NE #200, Atlanta, GA 30329, USA
| | - G Andrew James
- University of Arkansas for Medical Sciences, Brain Imaging Research Center, 4301 W. Markham Street #554, Little Rock, AR 72205, USA
| | - Josh M Cisler
- The University of Texas at Austin, Department of Psychiatry and Behavioral Sciences, Health Discovery Building, 1601 Trinity St., Building B, Austin, TX 78712, USA
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Ney LJ, Crombie KM, Mayo LM, Felmingham KL, Bowser T, Matthews A. Translation of animal endocannabinoid models of PTSD mechanisms to humans: Where to next? Neurosci Biobehav Rev 2021; 132:76-91. [PMID: 34838529 DOI: 10.1016/j.neubiorev.2021.11.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 12/11/2022]
Abstract
The endocannabinoid system is known to be involved in mechanisms relevant to PTSD aetiology and maintenance, though this understanding is mostly based on animal models of the disorder. Here we review how human paradigms can successfully translate animal findings to human subjects, with the view that substantially increased insight into the effect of endocannabinoid signalling on stress responding, emotional and intrusive memories, and fear extinction can be gained using modern paradigms and methods for assessing the state of the endocannabinoid system in PTSD.
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Affiliation(s)
- Luke J Ney
- School of Psychological Sciences, University of Tasmania, Australia; School of Psychology and Counselling, Queensland University of Technology, Australia.
| | - Kevin M Crombie
- Department of Psychiatry and Behavioral Sciences, University of Texas at Austin, United States
| | - Leah M Mayo
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Science, Linköping University, Sweden
| | - Kim L Felmingham
- Department of Psychological Sciences, University of Melbourne, Australia
| | | | - Allison Matthews
- School of Psychological Sciences, University of Tasmania, Australia
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