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Schrock JM. Accelerated aging in people living with HIV: The neuroimmune feedback model. Brain Behav Immun Health 2024; 36:100737. [PMID: 38356933 PMCID: PMC10864877 DOI: 10.1016/j.bbih.2024.100737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/02/2024] [Accepted: 02/04/2024] [Indexed: 02/16/2024] Open
Abstract
People living with HIV (PLWH) experience earlier onset of aging-related comorbidities compared to their counterparts without HIV. This paper lays out a theoretical model to explain why PLWH experience accelerated aging. Briefly, the model is structured as follows. PLWH experience disproportionately heavy burdens of psychosocial stress across the life course. This psychosocial stress increases risks for depressive symptoms and problematic substance use. Depressive symptoms and problematic substance use interfere with long-term adherence to antiretroviral therapy (ART). Lower ART adherence, in turn, exacerbates the elevated systemic inflammation stemming from HIV infection. This inflammation increases risks for aging-related comorbidities. Systemic inflammation also reduces connectivity in the brain's central executive network (CEN), a large-scale brain network that is critical for coping with stressful circumstances. This reduced capacity for coping with stress leads to further increases in depressive symptoms and problematic substance use. Together, these changes form a neuroimmune feedback loop that amplifies the impact of psychosocial stress on aging-related comorbidities. In this paper, I review the existing evidence relevant to this model and highlight directions for future research.
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Affiliation(s)
- Joshua M. Schrock
- Institute for Sexual and Gender Minority Health and Wellbeing, Northwestern University, 625 N. Michigan Avenue, Suite 1400, Chicago, IL, 60611, United states
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Parent-Roberge H, Fontvieille A, Maréchal R, Wagner R, Fülöp T, Pavic M, Riesco E. Effects of combined exercise training on the inflammatory profile of older cancer patients treated with systemic therapy. Brain Behav Immun Health 2020; 2:100016. [PMID: 38377414 PMCID: PMC8474500 DOI: 10.1016/j.bbih.2019.100016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 11/23/2019] [Indexed: 12/02/2022] Open
Abstract
Cancer-related fatigue (CRF) is a major issue in older cancer patients as it is associated with functional decline and a lower quality of life, and an increased inflammatory activity during cancer therapy is suspected to play a key role in CRF etiology. Combined aerobic and resistance exercise training is known to reduce CRF, and this could be mediated by a protective effect against this increased inflammatory activity. Hence, the main objective was to measure the effect of a 12-week combined exercise training on the inflammatory profile of older cancer patients undergoing systemic therapy. A secondary objective was to verify if there was an association between inflammatory profile and CRF. Methods Twenty older non-metastatic cancer patients initiating chemotherapy and/or hormone therapy were randomly assigned to 12 weeks of supervised, combined exercise or a control group (static stretching). Primary outcomes were the inflammatory profile, Indoleamine 2,3-deoxygenase activity (KYN/TRP ratio), and CRF (FACIT-F questionnaire). Control outcomes were the fasting nutritional and hormonal blood profiles, body composition (iDXA), physical activity habits (PASE questionnaire), nutritional habits (3-day log), and treatment-related variables. Results No worsening of the inflammatory profile was observed in both arms of the study after the intervention. No significant change in CRF was observed, although there was a trend for a reduction in the experimental group (p = 0.10). Significant correlations were found at both timepoints between the KYN/TRP ratio and the delay with the previous treatment received (p ≤ 0.03). Conclusion These results suggest that exercise might have elicited a positive effect on CRF, which was not mediated by the modulation of the pro-inflammatory cytokine profile. However, the decrease in IL-6/IL-10 ratio in the exercise group might reflect a possible anti-inflammatory effect of exercise. Moreover, exploratory analyses suggest that an acute effect of chemotherapy treatments influenced the inflammatory profile measurements, which could explain the absence of change in the fasting inflammatory profile.
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Affiliation(s)
- Hugo Parent-Roberge
- University of Sherbrooke, Faculty of Physical Activity Sciences, 2500, boul. de l’Université, Sherbrooke, QC, J1K 2R1, Canada
- Research Centre on Aging, affiliated with CIUSSS de l’Estrie - CHUS, 1036, rue Belvédère sud, Sherbrooke, QC, J1H 4C4, Canada
| | - Adeline Fontvieille
- University of Sherbrooke, Faculty of Physical Activity Sciences, 2500, boul. de l’Université, Sherbrooke, QC, J1K 2R1, Canada
- Research Centre on Aging, affiliated with CIUSSS de l’Estrie - CHUS, 1036, rue Belvédère sud, Sherbrooke, QC, J1H 4C4, Canada
| | - René Maréchal
- University of Sherbrooke, Faculty of Physical Activity Sciences, 2500, boul. de l’Université, Sherbrooke, QC, J1K 2R1, Canada
- Research Centre on Aging, affiliated with CIUSSS de l’Estrie - CHUS, 1036, rue Belvédère sud, Sherbrooke, QC, J1H 4C4, Canada
| | - Richard Wagner
- University of Sherbrooke, Faculty of Medicine and Health Sciences, 3001, 12e avenue Nord, Sherbrooke, QC, J1H 5N4, Canada
- Centre de recherche du CHUS, Sherbrooke, QC, J1H 5N4, Canada
| | - Tamàs Fülöp
- Research Centre on Aging, affiliated with CIUSSS de l’Estrie - CHUS, 1036, rue Belvédère sud, Sherbrooke, QC, J1H 4C4, Canada
- University of Sherbrooke, Faculty of Medicine and Health Sciences, 3001, 12e avenue Nord, Sherbrooke, QC, J1H 5N4, Canada
- Centre de recherche du CHUS, Sherbrooke, QC, J1H 5N4, Canada
| | - Michel Pavic
- University of Sherbrooke, Faculty of Medicine and Health Sciences, 3001, 12e avenue Nord, Sherbrooke, QC, J1H 5N4, Canada
- Centre de recherche du CHUS, Sherbrooke, QC, J1H 5N4, Canada
| | - Eléonor Riesco
- University of Sherbrooke, Faculty of Physical Activity Sciences, 2500, boul. de l’Université, Sherbrooke, QC, J1K 2R1, Canada
- Research Centre on Aging, affiliated with CIUSSS de l’Estrie - CHUS, 1036, rue Belvédère sud, Sherbrooke, QC, J1H 4C4, Canada
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Phillips C, Fahimi A. Immune and Neuroprotective Effects of Physical Activity on the Brain in Depression. Front Neurosci 2018; 12:498. [PMID: 30093853 PMCID: PMC6070639 DOI: 10.3389/fnins.2018.00498] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 07/03/2018] [Indexed: 12/13/2022] Open
Abstract
Physical activity-a lifestyle factor that is associated with immune function, neuroprotection, and energy metabolism-modulates the cellular and molecular processes in the brain that are vital for emotional and cognitive health, collective mechanisms that can go awry in depression. Physical activity optimizes the stress response, neurotransmitter level and function (e.g., serotonergic, noradrenergic, dopaminergic, and glutamatergic), myokine production (e.g., interleukin-6), transcription factor levels and correlates [e.g., peroxisome proliferator-activated receptor C coactivator-1α [PGC-1α], mitochondrial density, nitric oxide pathway activity, Ca2+ signaling, reactive oxygen specie production, and AMP-activated protein kinase [AMPK] activity], kynurenine metabolites, glucose regulation, astrocytic health, and growth factors (e.g., brain-derived neurotrophic factor). Dysregulation of these interrelated processes can effectuate depression, a chronic mental illness that affects millions of individuals worldwide. Although the biogenic amine model has provided some clinical utility in understanding chronic depression, a need remains to better understand the interrelated mechanisms that contribute to immune dysfunction and the means by which various therapeutics mitigate them. Fortunately, convergent evidence suggests that physical activity improves emotional and cognitive function in persons with depression, particularly in those with comorbid inflammation. Accordingly, the aims of this review are to (1) underscore the link between inflammatory correlates and depression, (2) explicate immuno-neuroendocrine foundations, (3) elucidate evidence of neurotransmitter and cytokine crosstalk in depressive pathobiology, (4) determine the immunomodulatory effects of physical activity in depression, (5) examine protocols used to effectuate the positive effects of physical activity in depression, and (6) highlight implications for clinicians and scientists. It is our contention that a deeper understanding of the mechanisms by which inflammation contributes to the pathobiology of depression will translate to novel and more effective treatments, particularly by identifying relevant patient populations that can benefit from immune-based therapies within the context of personalized medicine.
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Affiliation(s)
- Cristy Phillips
- Physical Therapy, Arkansas State University, Jonesboro, AR, United States
- Physical Therapy, University of Tennessee Health Science Center, Memphis, TN, United States
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Kołosowska K, Maciejak P, Szyndler J, Turzyńska D, Sobolewska A, Płaźnik A. The role of IL-1β and glutamate in the effects of lipopolysaccharide on the hippocampal electrical kindling of seizures. J Neuroimmunol 2016; 298:146-52. [PMID: 27609288 DOI: 10.1016/j.jneuroim.2016.07.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/28/2016] [Accepted: 07/20/2016] [Indexed: 11/28/2022]
Abstract
In our study, we used rapid electrical hippocampal kindling and in vivo microdialysis methods to assess the involvement of inflammatory mediators: lipopolysaccharide (LPS) and proinflammatory interleukin-1β (IL-1β) in mechanisms of epileptogenesis. We observed, that both, LPS and IL-1β, administered into stimulated hippocampus, accelerated kindling process. LPS also increased the expression of IL-1β in stimulated hippocampus in kindled rats. In vivo acute LPS perfusion, via a microdialysis cannula implanted into the naïve rat's hippocampus, produced an increase in extracellular glutamate release. We suppose, that particularly IL-1β action and increased glutamate concentration may significantly contribute to LPS effects on kindling development.
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Affiliation(s)
- Karolina Kołosowska
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland.
| | - Piotr Maciejak
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland; Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
| | - Janusz Szyndler
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Danuta Turzyńska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
| | - Alicja Sobolewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
| | - Adam Płaźnik
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland; Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
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Guo Y, Cai H, Chen L, Liang D, Yang R, Dang R, Jiang P. Quantitative profiling of neurotransmitter abnormalities in the hippocampus of rats treated with lipopolysaccharide: Focusing on kynurenine pathway and implications for depression. J Neuroimmunol 2016; 295-296:41-6. [DOI: 10.1016/j.jneuroim.2016.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 04/05/2016] [Accepted: 04/08/2016] [Indexed: 01/03/2023]
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Sharma N, Nehru B. Characterization of the lipopolysaccharide induced model of Parkinson's disease: Role of oxidative stress and neuroinflammation. Neurochem Int 2015; 87:92-105. [PMID: 26055970 DOI: 10.1016/j.neuint.2015.06.004] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 05/11/2015] [Accepted: 06/03/2015] [Indexed: 01/28/2023]
Abstract
INTRODUCTION Primary pathology underlying Parkinson's disease (PD) is the loss of dopaminergic neurons in the substantia nigra (SN). A variety of genetic and environmental factors underlie this loss of dopaminergic neurons. However, recent studies have highlighted the role of elevated oxidative stress and the pro-inflammatory responses contributing to or exacerbating the nigrostriatal degeneration. METHODS With the establishment of neuroinflammation as an important process involved in the PD pathogenesis, in the present study this pathogenic feature was replicated in animals using lipopolysaccharide (LPS) (5 ug/5 ul PBS) infused stereotaxically into the SN of rats. RESULTS LPS injected into the SN successfully replicated the pathogenic features of PD in rats as it elicited an inflammatory response via action of microglia. LPS infusion resulted in glial cell activation as depicted from immunohistochemistry (IHC) analysis of GFAP and Iba-1. Also, a significant increase in the mRNA expression of proinflammatory cytokines, i.e. TNF-α and IL-1β, was observed after 7 days of LPS infusion whereas the alterations in the oxidative stress markers, i.e ROS, lipid peroxidation, NO formation, NADPH oxidase activity, glutathione system, SOD and catalase, became highly significant after 14 days of infusion. As a consequence, after 21 days of LPS infusion we observed activation of apoptotic pathway indicated by increased expression of caspases 3 and caspase 9. This was followed by a significant decline in the expression of tyrosine hyroxylase (TH) as revealed by IHC. Further, there was a marked decrease in the level of dopamine and its metabolites enough for the production of behavioral abnormality in rats. CONCLUSION Hence, the present study provides extensive characterization of LPS induced model of PD. Study also confirms the co-existence and complex interplay between inflammation and oxidative stress contributing equally to the dopaminergic neuronal degeneration process in PD.
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Affiliation(s)
- Neha Sharma
- Department of Biophysics, Panjab University, Chandigarh 160014, India.
| | - Bimla Nehru
- Department of Biophysics, Panjab University, Chandigarh 160014, India.
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Eidson LN, Murphy AZ. Blockade of Toll-like receptor 4 attenuates morphine tolerance and facilitates the pain relieving properties of morphine. J Neurosci 2013; 33:15952-63. [PMID: 24089500 PMCID: PMC3787504 DOI: 10.1523/jneurosci.1609-13.2013] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 08/26/2013] [Accepted: 08/27/2013] [Indexed: 11/21/2022] Open
Abstract
The ventrolateral periaqueductal gray (vlPAG) is an integral locus for morphine action. Although it is clear that glia contribute to the development of morphine tolerance, to date, the investigation of their role has been limited to spinal and medullary loci. Opioids induce a neuroinflammatory response that opposes acute and long-term analgesia, thereby limiting their efficacy as therapeutic agents. Recent data suggest that the innate immune receptor Toll-like receptor 4 (TLR4), along with its coreceptor myeloid differentiation factor-2 (MD-2), mediates these effects. To date, the brain loci through which TLR4 modulates morphine tolerance have not been identified. We have previously demonstrated that chronic subcutaneous morphine results in tolerance that is accompanied by increases in vlPAG glial cell activity. Using in vivo pharmacological manipulations of vlPAG glia and TLR4 in the adult male rat, we show that intra-vlPAG administration of the general glial cell metabolic inhibitor propentofylline or the astrocyte activity inhibitor fluorocitrate attenuate tolerance to morphine. Characterization of MD-2 expression within the PAG revealed dense MD-2 expression throughout the vlPAG. Further, antagonizing vlPAG TLR4 dose dependently prevented the development of morphine tolerance, and vlPAG microinjections of TLR4 agonists dose dependently produced a "naive" tolerance to subsequent challenge doses of morphine. Finally, using a model of persistent inflammatory pain and pharmacological manipulation of TLR4 we demonstrate that systemic antagonism of TLR4 potentiated acute morphine antihyperalgesia. These results, together, indicate that vlPAG glia regulate morphine tolerance development via TLR4 signaling, and implicate TLR4 as a potential therapeutic target for the treatment of pain.
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Affiliation(s)
- Lori N. Eidson
- Neuroscience Institute, Georgia State University, Atlanta, Georgia 30303
| | - Anne Z. Murphy
- Neuroscience Institute, Georgia State University, Atlanta, Georgia 30303
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Cytokine effects on the basal ganglia and dopamine function: the subcortical source of inflammatory malaise. Front Neuroendocrinol 2012; 33:315-27. [PMID: 23000204 PMCID: PMC3484236 DOI: 10.1016/j.yfrne.2012.09.003] [Citation(s) in RCA: 257] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 08/28/2012] [Accepted: 09/12/2012] [Indexed: 01/18/2023]
Abstract
Data suggest that cytokines released during the inflammatory response target subcortical structures including the basal ganglia as well as dopamine function to acutely induce behavioral changes that support fighting infection and wound healing. However, chronic inflammation and exposure to inflammatory cytokines appears to lead to persisting alterations in the basal ganglia and dopamine function reflected by anhedonia, fatigue, and psychomotor slowing. Moreover, reduced neural responses to hedonic reward, decreased dopamine metabolites in the cerebrospinal fluid and increased presynaptic dopamine uptake and decreased turnover have been described. This multiplicity of changes in the basal ganglia and dopamine function suggest fundamental effects of inflammatory cytokines on dopamine synthesis, packaging, release and/or reuptake, which may sabotage and circumvent the efficacy of current treatment approaches. Thus, examination of the mechanisms by which cytokines alter the basal ganglia and dopamine function will yield novel insights into the treatment of cytokine-induced behavioral changes and inflammatory malaise.
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Tufekci KU, Genc S, Genc K. The endotoxin-induced neuroinflammation model of Parkinson's disease. PARKINSON'S DISEASE 2011; 2011:487450. [PMID: 21331154 PMCID: PMC3034925 DOI: 10.4061/2011/487450] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/18/2010] [Accepted: 12/16/2010] [Indexed: 01/22/2023]
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the progressive loss of dopaminergic (DA) neurons in the substantia nigra. Although the exact cause of the dopaminergic neurodegeneration remains elusive, recent postmortem and experimental studies have revealed an essential role for neuroinflammation that is initiated and driven by activated microglial and infiltrated peripheral immune cells and their neurotoxic products (such as proinflammatory cytokines, reactive oxygen species, and nitric oxide) in the pathogenesis of PD. A bacterial endotoxin-based experimental model of PD has been established, representing a purely inflammation-driven animal model for the induction of nigrostriatal dopaminergic neurodegeneration. This model, by itself or together with genetic and toxin-based animal models, provides an important tool to delineate the precise mechanisms of neuroinflammation-mediated dopaminergic neuron loss. Here, we review the characteristics of this model and the contribution of neuroinflammatory processes, induced by the in vivo administration of bacterial endotoxin, to neurodegeneration. Furthermore, we summarize the recent experimental therapeutic strategies targeting endotoxin-induced neuroinflammation to elicit neuroprotection in the nigrostriatal dopaminergic system. The potential of the endotoxin-based PD model in the development of an early-stage specific diagnostic biomarker is also emphasized.
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Affiliation(s)
- Kemal Ugur Tufekci
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| | - Sermin Genc
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| | - Kursad Genc
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
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Eisenberger NI, Berkman ET, Inagaki TK, Rameson LT, Mashal NM, Irwin MR. Inflammation-induced anhedonia: endotoxin reduces ventral striatum responses to reward. Biol Psychiatry 2010; 68:748-54. [PMID: 20719303 PMCID: PMC3025604 DOI: 10.1016/j.biopsych.2010.06.010] [Citation(s) in RCA: 411] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 06/08/2010] [Accepted: 06/12/2010] [Indexed: 12/18/2022]
Abstract
BACKGROUND Although inflammatory activity is known to play a role in depression, no work has examined whether experimentally induced systemic inflammation alters neural activity that is associated with anhedonia, a key diagnostic symptom of depression. To investigate this, we examined the effect of an experimental inflammatory challenge on the neural correlates of anhedonia-namely, reduced ventral striatum (VS) activity to reward cues. We also examined whether this altered neural activity related to inflammatory-induced increases in depressed mood. METHODS Participants (n = 39) were randomly assigned to receive either placebo or low-dose endotoxin, which increases proinflammatory cytokine levels in a safe manner. Cytokine levels were repeatedly assessed through hourly blood draws; self-reported and observer-rated depressed mood were assessed regularly as well. Two hours after drug administration, neural activity was recorded as participants completed a task in which they anticipated monetary rewards. RESULTS Results demonstrated that subjects exposed to endotoxin, compared with placebo, showed greater increases in self-reported and observer-rated depressed mood over time, as well as significant reductions in VS activity to monetary reward cues. Moreover, the relationship between exposure to inflammatory challenge and increases in observer-rated depressed mood was mediated by between-group differences in VS activity to anticipated reward. CONCLUSIONS The data reported here show, for the first time, that inflammation alters reward-related neural responding in humans and that these reward-related neural responses mediate the effects of inflammation on depressed mood. As such, these findings have implications for understanding risk of depression in persons with underlying inflammation.
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