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- Case, Laura K., et al.
(författare)
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Pleasant Deep Pressure : Expanding the Social Touch Hypothesis
- 2021
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Ingår i: Neuroscience. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0306-4522 .- 1873-7544. ; 464
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Tidskriftsartikel (refereegranskat)abstract
- Neuroscientific research on pleasant touch has focused on the C-tactile pathway for gentle stroking and has successfully explained how these sensory fibers transmit information about affective social touch to the brain and induce sensations of pleasantness. The C-tactile social/affective touch hypothesis even proposes that C-tactile fibers form a privileged pathway underlying social touch. However, deep pressure is a type of touch commonly considered pleasant and calming, occurring in hugs, cuddling, and massage. In this paper we introduce a paradigm for studying pleasant deep pressure and propose that it constitutes another important form of social touch. We describe development of the oscillating compression sleeve (OCS) as one approach to administering deep pressure and demonstrate that this touch is perceived as pleasant and calming. Further, we show that deep pressure can be imaged with functional magnetic resonance imaging (MRI) using the air-pressure driven OCS and that deep pressure activates brain regions highly similar to those that respond to C-tactile stroking, as well as regions not activated by stroking. We propose that deep pressure constitutes another social touch pathway of evolutionary importance signaling the close proximity of conspecifics. This article is part of a Special Issue entitled: The Neurobiology of Social and Affective Touch. (c) 2020 The Authors. Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). research on pleasant touch has focused on the C-tactile pathway for gentle stroking and has successfully explained how these sensory fibers transmit information about affective social touch to the brain and induce sensations of pleasantness. The C-tactile social/affective touch hypothesis even proposes that C-tactile fibers form a privileged pathway underlying social touch. However, deep pressure is a type of touch commonly considered pleasant and calming, occurring in hugs, cuddling, and massage. In this paper we introduce a paradigm for studying pleasant deep pressure and propose that it constitutes another important form of social touch. We describe development of the oscillating compression sleeve (OCS) as one approach to administering deep pressure and demonstrate that this touch is perceived as pleasant and calming. Further, we show that deep pressure can be imaged with functional magnetic resonance imaging (MRI) using the air-pressuredriven OCS and that deep pressure activates brain regions highly similar to those that respond to C-tactile stroking, as well as regions not activated by stroking. We propose that deep pressure constitutes another social touch pathway of evolutionary importance signaling the close proximity of conspecifics. This article is part of a Special Issue entitled: The Neurobiology of Social and Affective Touch. (c) 2020 The Authors. Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).
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| 4. |
- Delfin, Carl, 1986, et al.
(författare)
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Exploring the Effects of an Acute Dose of Antipsychotic Medication on Motivation-mediated BOLD Activity Using fMRI and a Perceptual Decision-making Task
- 2020
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Ingår i: Neuroscience. - : Elsevier BV. - 0306-4522 .- 1873-7544. ; 440, s. 146-159
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Tidskriftsartikel (refereegranskat)abstract
- The left inferior frontal gyrus and the bilateral ventral striatum are thought to be involved in motivation-mediated decision-making. Antipsychotics may influence this relationship, and atypical antipsychotics improve secondary negative symptoms in schizophrenia, such as loss of motivation, although the acute effects of pharmacological medication on motivation are not fully understood. In this single-blinded, randomized controlled trial, 49 healthy volunteers were randomized into three groups to receive a single dose of haloperidol, aripiprazole or placebo. Between 4.0 and 5.6 h later, participant's brain blood-oxygen-level dependent (BOLD) activity was recorded using functional magnetic resonance imaging (fMRI) while completing a perceptual decision-making fMRI task consisting of one neutral and one motivated condition. Response bias, reflecting the participant's willingness to say that the target stimulus is present, was calculated using signal detection theory. Concurrent with widespread changes in BOLD signal in the motivated vs. neutral condition, a less conservative, mathematically optimal response bias was observed in the motivated condition across the whole sample. Within-group differences in BOLD signal in the left inferior frontal gyrus and bilateral ventral striatum were observed between conditions in the aripiprazole and haloperidol groups, but not in the placebo group. No robust between-group differences in brain activity in the left inferior frontal gyrus or the bilateral ventral striatum were found. Overall, we found no robust evidence for an effect of either aripiprazole or haloperidol on motivationally mediated behavior. An interesting pattern of correlations possibly related to pharmacologically induced alterations in the dopamine system was observed, although findings remain inconclusive and must be replicated in larger samples. (C) 2020 IBRO. Published by Elsevier Ltd. All rights reserved.
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| 5. |
- Delfin, Carl, et al.
(författare)
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Structural Brain Correlates of the Externalizing Spectrum in Young Adults
- 2021
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Ingår i: Neuroscience. - : Elsevier BV. - 0306-4522. ; 463, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The externalizing spectrum, including traits and behaviors such as aggression, reduced inhibitiory control and substance abuse, is associated with altered prefrontal brain morphology. However, the degree to which different manifestations of the externalizing spectrum are associated with distinct or overlapping variations in individual brain morphology is unclear. Here, we therefore used structural magnetic resonance imaging, self-report assessment, and a response inhibition task in a sample of 59 young adults to examine how cortical thickness in the anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and dorsolateral prefrontal cortex (DLPFC) relate to four different manifestations of the externalizing spectrum: disinhibition, callous aggression, substance abuse, and behavioral inhibitory control. Using Bayesian linear regression models controlling for age, gender, and years of education, we found that the different manifestations of the externalizing spectrum were associated with both distinct and overlapping morphology variations. Specifically, both callous aggression and inhibitory control was associated with increased cortical thickness of the OFC, a region involved in reward processing, decision-making, and regulation of anxiety and fear. Both disinhibition and substance abuse were associated with DLPFC thickness, although with opposite association patterns, possibly reflecting processes related to inhibitory control, working memory and attention. Moreover, disinhibition, but not callous aggression or substance abuse, was associated with behavioral inhibitory control. Our results provide further support for the link between externalizing behaviors and prefrontal brain morphology, while identifying distinct prefrontal areas associated with different clinically relevant manifestations. These findings may help guide further research aimed at developing novel treatment and intervention strategies for externalizing behaviors and disorders.
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| 6. |
- Devarakonda, Sravani, et al.
(författare)
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Dietary Fiber and the Hippocampal Neurogenic Niche in a Model of Pelvic Radiotherapy
- 2021
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Ingår i: Neuroscience. - : Elsevier BV. - 0306-4522. ; 475, s. 137-147
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Tidskriftsartikel (refereegranskat)abstract
- sought to determine whether radiation to the colorectum had an impact on parameters of hippocampal neurogenesis and, if so, whether it could be modulated by a fiber-rich diet. Male C57BL/6J mice were fed a diet containing bioprocessed oat bran or a fiber-free diet, starting two weeks before colorectal irradiation with 4 fractions of 8 Gray or sham-irradiation. Diets were then continued for 1, 6 or 18 weeks, whereafter parameters of hippocampal neurogenesis were analyzed and correlated to serum cytokine levels. No statistically significant changes in neuronal markers or cell proliferation were found at one week post-irradiation. Six weeks postirradiation there was a decreased cell proliferation in the subgranular zone that appeared slightly more pronounced in irradiated animals on a fiber-free diet and increased numbers of immature neurons per mm2 dentate gyrus in the irradiated mice, with a statistically significant increase in mice on a fiber-rich diet. Microglial abundancy was similar between all groups. 18 weeks post-irradiation, a fiber-free diet had reduced the number of immature neurons, whereas irradiation resulted in an increase. Despite this, the population of mature neurons was stable. Analysis of serum cytokines revealed a negative correlation between MIP1-a and the number of immature neurons one week after irradiation, regardless of diet. Our findings show that pelvic radiotherapy has the potential to cause a long-lasting impact on hippocampal neurogenesis, and dietary interventions may modulate this impact. More in-depth studies on the relationship between irradiation-induced intestinal injury and brain health are warranted. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 7. |
- Flores-Maldonado, Catalina, et al.
(författare)
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A Low Cost Antibody Signal Enhancer Improves Immunolabeling in Cell Culture, Primate Brain and Human Cancer Biopsy
- 2020
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Ingår i: Neuroscience. - : Elsevier. - 0306-4522 .- 1873-7544. ; 439, s. 275-286
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Tidskriftsartikel (refereegranskat)abstract
- The use of antibodies to identify neuronal receptors, neurotransmitters, cytoskeletal elements or pathologic protein aggregates, ion channels, adhesion molecules or other cell-type specific markers, is common practice in neuroscience. Antibody detection systems are often based on confocal, epifluorescence or brightfield microscopy. Three types of technical issues can interfere with immunolabeling: low abundance of the target protein, low specific affinity of the antibody and/or signal background sometimes related to tissue fixation. Here, giving tribute to Professor Miledis mentorship, we propose the application of an antibody signal enhancer (ASE) solution based on glycine, hydrogen peroxide and a detergent mix as a simple, low cost, protocol variation that significantly and specifically improves the signal to noise ratio during immunostaining experiments. We describe three new settings in which ASE improves the detection of a variety of antibodies applied on long-time stored non-human primate brain sections, cell culture monolayers and on squamous carcinomas retrieved from cervical cancer patients. The significant improvement of ASE over optimized immunohistochemical protocols used in clinical practice (i.e. cancer detection) combined with its simplicity and low cost makes it an attractive method for biomedical applications. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries. (C) 2020 IBRO. Published by Elsevier Ltd. All rights reserved.
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| 10. |
- Mcintyre, Sarah, 1981-, et al.
(författare)
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The Effects of Ageing on Tactile Function in Humans
- 2021
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Ingår i: Neuroscience. - : Elsevier. - 0306-4522 .- 1873-7544. ; 464, s. 53-58
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Forskningsöversikt (refereegranskat)abstract
- Ageing is accompanied by a steady decline in touch sensitivity and acuity. Conversely, pleasant touch, such as experienced during a caress, is even more pleasant in old age. There are many physiological changes that might explain these perceptual changes, but researchers have not yet identified any specific mechanisms. Here, we review both the perceptual and structural changes to the touch system that are associated with ageing. The structural changes include reduced elasticity of the skin in older people, as well as reduced numbers and altered morphology of skin tactile receptors. Effects of ageing on the peripheral and central nervous systems include demyelination, which affects the timing of neural signals, as well as reduced numbers of peripheral nerve fibres. The ageing brain also undergoes complex changes in blood flow, metabolism, plasticity, neurotransmitter function, and, for touch, the body map in primary somatosensory cortex. Although several studies have attempted to find a direct link between perceptual and structural changes, this has proved surprisingly elusive. We also highlight the need for more evidence regarding age-related changes in peripheral nerve function in the hairy skin, as well as the social and emotional aspects of touch.
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