Brain, behavior, and immunity
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Brain Behav. Immun. · Aug 2020
Randomized Controlled TrialImpact of acute inflammation on the extinction of aversive gut memories.
Impaired extinction of pain-related fear memories can lead to persistent or resurging fear of pain, contributing to the development and maintenance of chronic pain conditions. The mechanisms underlying maladaptive pain-related learning and memory processes remain incompletely understood, particularly in the context of interoceptive, visceral pain. Inflammation is known to interfere with learning and memory, but its effects on the extinction of pain-related fear memories have never been tested. ⋯ Despite pronounced LPS-induced effects on inflammatory markers, cortisol, and negative affect, we did not find evidence that acute inflammation resulted in altered fear extinction. The findings support the notion that visceral pain-related fear learning establishes a robust aversive memory trace that remains preserved during inhibitory learning, leaving a latent vulnerability for the return of fear. Inflammation during inhibitory learning did neither weaken nor further amplify this aversive memory trace, suggesting that it is rather resistant to acute inflammation-induced effects, at least in healthy individuals with no additional vulnerability factors.
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Brain Behav. Immun. · Aug 2020
Multicenter StudyA multinational, multicentre study on the psychological outcomes and associated physical symptoms amongst healthcare workers during COVID-19 outbreak.
Since the declaration of the coronavirus 2019 (COVID-19) outbreak as pandemic, there are reports on the increased prevalence of physical symptoms observed in the general population. We investigated the association between psychological outcomes and physical symptoms among healthcare workers. ⋯ Our study demonstrates a significant association between the prevalence of physical symptoms and psychological outcomes among healthcare workers during the COVID-19 outbreak. We postulate that this association may be bi-directional, and that timely psychological interventions for healthcare workers with physical symptoms should be considered once an infection has been excluded.
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Brain Behav. Immun. · Aug 2020
PARP-1-regulated TNF-α expression in the dorsal root ganglia and spinal dorsal horn contributes to the pathogenesis of neuropathic pain in rats.
Emerging evidence has implicated poly-(ADP-ribose) polymerase 1 (PARP-1), a transcriptional coregulator, in a variety of inflammatory diseases. In the current study, the role of PARP-1 in neuropathic pain and the underlying mechanisms were investigated. Neuropathic pain was determined by assessing the paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) following lumbar 5 spinal nerve ligation (SNL) in male rates. ⋯ Co-IP assay revealed that SNL caused a significant increase in the level of histone H1 poly(ADP)-ribosylation. Together, these results indicate that PARP-1-regulated TNF-α expression in the DRG and spinal dorsal horn following SNL contributes to the development and maintenance of neuropathic pain. Targeting PARP-1 might be a promising therapeutic strategy for the treatment of the chronic pain.
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Brain Behav. Immun. · Aug 2020
Germinal center formation, immunoglobulin production and hindlimb nociceptive sensitization after tibia fracture.
Emerging evidence suggests that Complex Regional Pain Syndrome (CRPS) is in part a post-traumatic autoimmune disease mediated by an adaptive immune response after limb injuries. We previously observed in a murine tibial fracture model of CRPS that pain-related behaviors were dependent upon adaptive immune mechanisms including the neuropeptide-dependent production of IgM for 5 months after injury. ⋯ We observed that: 1) IgM protein levels in the skin of the fractured mice were elevated at 3 weeks post fracture, but not at earlier time points, 2) serum from fracture mice at 3 weeks, but not 1 and 2 weeks post fracture, had pro-nociceptive effects when passively transferred to fractured muMT mice lacking B cells, 3) fracture induced popliteal lymphadenopathy occurred ipsilateral to fracture beginning at 1 week and peaking at 3 weeks post fracture, 4) a germinal center reaction was detected by FACS analysis in the popliteal lymph nodes from injured limbs by 3 weeks post fracture but not in other lymphoid tissues, 5) germinal center formation was characterized by the induction of T follicular helper cells (Tfh) and germinal center B cells in the popliteal lymph nodes of the injured but not contralateral limbs, and 6) fracture mice treated with the Tfh signaling inhibitor FK506 had impaired germinal center reactions, reduced IgM levels, reduced nociceptive sensitization, and no pronociceptive serum effects after administration to fractured muMT mice. Collectively these data demonstrate that tibia fracture induces an adaptive autoimmune response characterized by popliteal lymph node germinal center formation and Tfh cell dependent B cell activation, resulting in nociceptive sensitization within 3 weeks.
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Brain Behav. Immun. · Aug 2020
Review Meta AnalysisPrevalence of depression, anxiety, and insomnia among healthcare workers during the COVID-19 pandemic: A systematic review and meta-analysis.
COVID-19 pandemic has the potential to significantly affect the mental health of healthcare workers (HCWs), who stand in the frontline of this crisis. It is, therefore, an immediate priority to monitor rates of mood, sleep and other mental health issues in order to understand mediating factors and inform tailored interventions. The aim of this review is to synthesize and analyze existing evidence on the prevalence of depression, anxiety and insomnia among HCWs during the Covid-19 outbreak. ⋯ Early evidence suggests that a considerable proportion of HCWs experience mood and sleep disturbances during this outbreak, stressing the need to establish ways to mitigate mental health risks and adjust interventions under pandemic conditions.