55 research outputs found
impulsivity and the impact of contextual cues on instrumental behavior in alcohol dependence
Alcohol-related cues acquire incentive salience through Pavlovian conditioning
and then can markedly affect instrumental behavior of alcohol-dependent
patients to promote relapse. However, it is unclear whether similar effects
occur with alcohol-unrelated cues. We tested 116 early-abstinent alcohol-
dependent patients and 91 healthy controls who completed a delay discounting
task to assess choice impulsivity, and a Pavlovian-to-instrumental transfer
(PIT) paradigm employing both alcohol-unrelated and alcohol-related stimuli.
To modify instrumental choice behavior, we tiled the background of the
computer screen either with conditioned stimuli (CS) previously generated by
pairing abstract pictures with pictures indicating monetary gains or losses,
or with pictures displaying alcohol or water beverages. CS paired to money
gains and losses affected instrumental choices differently. This PIT effect
was significantly more pronounced in patients compared to controls, and the
group difference was mainly driven by highly impulsive patients. The PIT
effect was particularly strong in trials in which the instrumental stimulus
required inhibition of instrumental response behavior and the background CS
was associated to monetary gains. Under that condition, patients performed
inappropriate approach behavior, contrary to their previously formed
behavioral intention. Surprisingly, the effect of alcohol and water pictures
as background stimuli resembled that of aversive and appetitive CS,
respectively. These findings suggest that positively valenced background CS
can provoke dysfunctional instrumental approach behavior in impulsive alcohol-
dependent patients. Consequently, in real life they might be easily seduced by
environmental cues to engage in actions thwarting their long-term goals. Such
behaviors may include, but are not limited to, approaching alcohol
Existence of long-lasting experience-dependent plasticity in endocrine cell networks
Experience-dependent plasticity of cell and tissue function is critical for survival by allowing organisms to dynamically adjust physiological processes in response to changing or harsh environmental conditions. Despite the conferred evolutionary advantage, it remains unknown whether emergent experience-dependent properties are present in cell populations organized as networks within endocrine tissues involved in regulating body-wide homeostasis. Here we show, using lactation to repeatedly activate a specific endocrine cell network in situ in the mammalian pituitary, that templates of prior demand are permanently stored through stimulus-evoked alterations to the extent and strength of cell–cell connectivity. Strikingly, following repeat stimulation, evolved population behaviour leads to improved tissue output. As such, long-lasting experience-dependent plasticity is an important feature of endocrine cell networks and underlies functional adaptation of hormone release
Bishops who live like princes: Bishop Tebartz-van Elst and the challenge of defining corruption
This article contributes to the debate on defining corruption. Rather than attempting to provide a definitive definition, it uses the case of Franz-Peter Tebartz-van Elst, a German bishop from the diocese of Limburg who stepped down in 2014, to illustrate that the disciplines of law, political science, economics, and anthropology all make important contributions to understanding what corruption is and how it should be conceptualized. Seen through these different lenses, the article argues, the case of “Bishop Bling” can be understood in strikingly different ways. This has ramifications not just for the case itself but also for how analysts understand corruption more broadly. Adopting an overtly interdisciplinary approach does not represent a way to “solve” the definitional dilemma, but it can help analysts understand more about corruption’s multiplicity
The developmental impacts of natural selection on human pelvic morphology
Evolutionary responses to selection for bipedalism and childbirth have shaped the human pelvis, a structure that differs substantially from that in apes. Morphology related to these factors is present by birth, yet the developmental-genetic mechanisms governing pelvic shape remain largely unknown. Here, we pinpoint and characterize a key gestational window when human-specific pelvic morphology becomes recognizable, as the ilium and the entire pelvis acquire traits essential for human walking and birth. We next use functional genomics to molecularly characterize chondrocytes from different pelvic subelements during this window to reveal their developmental-genetic architectures. We then find notable evidence of ancient selection and genetic constraint on regulatory sequences involved in ilium expansion and growth, findings complemented by our phenotypic analyses showing that variation in iliac traits is reduced in humans compared to African apes. Our datasets provide important resources for musculoskeletal biology and begin to elucidate developmental mechanisms that shape human-specific morphology
Phenotype of antigen unexperienced T(H) cells in the inflamed central nervous system in experimental autoimmune encephalomyelitis
Multiple sclerosis is a chronic, disseminated inflammation of the central nervous system which is thought to be driven by autoimmune T cells. Genetic association studies in multiple sclerosis and a large number of studies in the animal model of the disease support a role for effector/memory T helper cells. However, the mechanisms underlying relapses, remission and chronic progression in multiple sclerosis or the animal model experimental autoimmune encephalomyelitis, are not clear. In particular, there is only scarce information on the role of central nervous system-invading naive T helper cells in these processes. By applying two-photon laser scanning microscopy we could show in vivo that antigen unexperienced T helper cells migrated into the deep parenchyma of the inflamed central nervous system in experimental autoimmune encephalomyelitis, independent of their antigen specificity. Using flow cytometric analyses of central nervous system-derived lymphocytes we found that only antigen-specific, formerly naive T helper cells became activated during inflammation of the central nervous system encountering their corresponding antigen
Strong seduction: impulsivity and the impact of contextual cues on instrumental behavior in alcohol dependence
Alcohol-related cues acquire incentive salience through Pavlovian conditioning and then can markedly affect instrumental behavior of alcohol-dependent patients to promote relapse. However, it is unclear whether similar effects occur with alcohol-unrelated cues. We tested 116 early-abstinent alcohol-dependent patients and 91 healthy controls who completed a delay discounting task to assess choice impulsivity, and a Pavlovian-to-instrumental transfer (PIT) paradigm employing both alcohol-unrelated and alcoholrelated stimuli. To modify instrumental choice behavior, we tiled the background of the computer screen either with conditioned stimuli (CS) previously generated by pairing abstract pictures with pictures indicating monetary gains or losses, or with pictures displaying alcohol or water beverages. CS paired to money gains and losses affected instrumental choices differently. This PIT effect was significantly more ronounced in patients compared to controls, and the group difference was mainly driven by highly impulsive patients. The PIT effect was particularly strong in trials in which the instrumental stimulus required inhibition of instrumental response behavior and the background CS was associated to monetary gains. Under that condition, patients
performed inappropriate approach behavior, contrary to their previously formed behavioral intention. Surprisingly, the effect of alcohol and water pictures as background stimuli resembled that of aversive and appetitive CS, respectively. These findings suggest that positively valenced background CS can provoke dysfunctional instrumental approach behavior in impulsive alcohol-dependent patients. Consequently, in real life they might be easily seduced by environmental cues to engage in actions thwarting their longterm goals. Such behaviors may include, but are not limited to, approaching alcohol.Peer Reviewe
FRET based ratiometric Ca2+ imaging to investigate immune-mediated neuronal and axonal damage processes in experimental autoimmune encephalomyelitis
Background: Irreversible axonal and neuronal damage are the correlate of disability in patients suffering from multiple sclerosis (MS). A sustained increase of cytoplasmic free [Ca2+] is a common upstream event of many neuronal and axonal damage processes and could represent an early and potentially reversible step. New method: We propose a method to specifically analyze the neurodegenerative aspects of experimental autoimmune encephalomyelitis by Forster Resonance Energy Transfer (FRET) imaging of neuronal and axonal Ca2+ dynamics by two-photon laser scanning microscopy (TPLSM). Results: Using the genetically encoded Ca2+ sensor TN-XXL expressed in neurons and their corresponding axons, we confirm the increase of cytoplasmic free [Ca2+] in axons and neurons of autoimmune inflammatory lesions compared to those in non-inflamed brains. We show that these relative [Ca2+] increases were associated with immune-neuronal interactions. Comparison with existing methods: In contrast to Ca2+-sensitive dyes the use of a genetically encoded Ca2+ sensor allows reliable intraaxonal free [Ca2+] measurements in living anesthetized mice in health and disease. This method detects early axonal damage processes in contrast to e.g. cell/axon morphology analysis, that rather detects late signs of neurodegeneration. Conclusions: Thus, we describe a method to analyze and monitor early neuronal damage processes in the brain in vivo. (C) 2015 Elsevier B.V. All rights reserved
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