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1.
JBI Evid Synth ; 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34783713

RESUMO

OBJECTIVE: This scoping review will summarize what is known about formal and informal perinatal bereavement care guidelines used in health care facilities before discharge, and map the mental health outcomes of parents against characteristics of the guidelines. INTRODUCTION: Conflicting evidence for bereavement care guidelines, the lack of randomized controlled trials and experimental studies, and older synthesized information with a limited focus or population make synthesis complex. A scoping review will facilitate the process of determining the breadth and depth of the literature. INCLUSION CRITERIA: Sources pertaining to bereavement care guidelines used in health care facilities immediately after perinatal loss (miscarriage, stillbirth, or neonatal death) and measuring parents' mental health outcomes will be included. Sources relating to family members other than parents, perinatal loss occurring outside of a health care facility, and physical care guidelines will be excluded. METHODS: The proposed review will be conducted using JBI methodology for scoping reviews. The team will consider quantitative and qualitative studies, practice guidelines, case reports, expert opinions, systematic reviews, professional organization websites, and gray literature. Major databases to be searched will include CINAHL (EBSCO), PsycINFO (EBSCO), SocINDEX (EBSCO), Cochrane, Embase, MEDLINE (PubMed), and Web of Science. The earliest empirical study found (1976) will serve as the starting date limit. After pilot testing the two-step screening process (titles and abstracts, then full-text articles), data will be extracted, collated, and presented in narrative form as well as in tables and diagrams. The results will provide facilities with a broad view of bereavement care to support grieving parents' mental health.

2.
Front Syst Neurosci ; 15: 670702, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34393729

RESUMO

Stimulus-induced oscillations and synchrony among neuronal populations in visual cortex are well-established phenomena. Their functional role in cognition are, however, not well-understood. Recent studies have suggested that neural synchrony may underlie perceptual grouping as stimulus-frequency relationships and stimulus-dependent lateral connectivity profiles can determine the success or failure of synchronization among neuronal groups encoding different stimulus elements. We suggest that the same mechanism accounts for collinear facilitation and suppression effects where the detectability of a target Gabor stimulus is improved or diminished by the presence of collinear flanking Gabor stimuli. We propose a model of oscillators which represent three neuronal populations in visual cortex with distinct receptive fields reflecting the target and two flankers, respectively, and whose connectivity is determined by the collinearity of the presented Gabor stimuli. Our model simulations confirm that neuronal synchrony can indeed explain known collinear facilitation and suppression effects for attended and unattended stimuli.

3.
Nat Commun ; 12(1): 4839, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376673

RESUMO

The ability to maintain a sequence of items in memory is a fundamental cognitive function. In the rodent hippocampus, the representation of sequentially organized spatial locations is reflected by the phase of action potentials relative to the theta oscillation (phase precession). We investigated whether the timing of neuronal activity relative to the theta brain oscillation also reflects sequence order in the medial temporal lobe of humans. We used a task in which human participants learned a fixed sequence of pictures and recorded single neuron and local field potential activity with implanted electrodes. We report that spikes for three consecutive items in the sequence (the preferred stimulus for each cell, as well as the stimuli immediately preceding and following it) were phase-locked at distinct phases of the theta oscillation. Consistent with phase precession, spikes were fired at progressively earlier phases as the sequence advanced. These findings generalize previous findings in the rodent hippocampus to the human temporal lobe and suggest that encoding stimulus information at distinct oscillatory phases may play a role in maintaining sequential order in memory.


Assuntos
Potenciais de Ação/fisiologia , Epilepsia/fisiopatologia , Aprendizagem/fisiologia , Neurônios/fisiologia , Ritmo Teta/fisiologia , Adolescente , Adulto , Epilepsia/diagnóstico , Feminino , Hipocampo/citologia , Hipocampo/fisiologia , Humanos , Masculino , Modelos Neurológicos , Neurônios/citologia , Estimulação Luminosa/métodos , Lobo Temporal/citologia , Lobo Temporal/fisiologia , Adulto Jovem
4.
J Phys Chem B ; 125(36): 10213-10223, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34464136

RESUMO

Calorimetric and incoherent neutron scattering methods were employed to investigate the action of magainin 2 and PGLa peptides on the phase behavior and molecular dynamics of lipids mimicking cytoplasmic membranes of Gram-negative bacteria. The impact of the peptides, tested individually and cooperatively by differential scanning calorimetry, presented a broadened peak, sometimes with a second shoulder, depicting the phase transition temperature around 21 °C. Neutron scattering revealed a small but significant variation of the membrane dynamics due to the peptides in both in-plane and out-of-plane directions. Although we did not find a clear hint for synergy in the interplay of the two peptides, the calorimetric and neutron data give compatible results in terms of a decrease of the enthalpy due to the presence of the peptides, which destabilize the membrane. The dynamics in the two directions was differentiated when the individual peptides were added to the membranes, but the impact was smaller when both peptides were added together.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Bactérias Gram-Negativas , Bicamadas Lipídicas , Magaininas/química , Varredura Diferencial de Calorimetria , Membrana Celular , Simulação de Dinâmica Molecular , Termodinâmica
5.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34200063

RESUMO

The modification of archaeal lipid bilayer properties by the insertion of apolar molecules in the lipid bilayer midplane has been proposed to support cell membrane adaptation to extreme environmental conditions of temperature and hydrostatic pressure. In this work, we characterize the insertion effects of the apolar polyisoprenoid squalane on the permeability and fluidity of archaeal model membrane bilayers, composed of lipid analogues. We have monitored large molecule and proton permeability and Laurdan generalized polarization from lipid vesicles as a function of temperature and hydrostatic pressure. Even at low concentration, squalane (1 mol%) is able to enhance solute permeation by increasing membrane fluidity, but at the same time, to decrease proton permeability of the lipid bilayer. The squalane physicochemical impact on membrane properties are congruent with a possible role of apolar intercalants on the adaptation of Archaea to extreme conditions. In addition, such intercalant might be used to cheaply create or modify chemically resistant liposomes (archeaosomes) for drug delivery.


Assuntos
Archaea/fisiologia , Membrana Celular/fisiologia , Bicamadas Lipídicas/metabolismo , Lipossomos/metabolismo , Fluidez de Membrana , Esqualeno/análogos & derivados , Archaea/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Esqualeno/farmacologia , Temperatura
6.
Commun Biol ; 4(1): 653, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34079059

RESUMO

It has been proposed that adaptation to high temperature involved the synthesis of monolayer-forming ether phospholipids. Recently, a novel membrane architecture was proposed to explain the membrane stability in polyextremophiles unable to synthesize such lipids, in which apolar polyisoprenoids populate the bilayer midplane and modify its physico-chemistry, extending its stability domain. Here, we have studied the effect of the apolar polyisoprenoid squalane on a model membrane analogue using neutron diffraction, SAXS and fluorescence spectroscopy. We show that squalane resides inside the bilayer midplane, extends its stability domain, reduces its permeability to protons but increases that of water, and induces a negative curvature in the membrane, allowing the transition to novel non-lamellar phases. This membrane architecture can be transposed to early membranes and could help explain their emergence and temperature tolerance if life originated near hydrothermal vents. Transposed to the archaeal bilayer, this membrane architecture could explain the tolerance to high temperature in hyperthermophiles which grow at temperatures over 100 °C while having a membrane bilayer. The induction of a negative curvature to the membrane could also facilitate crucial cell functions that require high bending membranes.


Assuntos
Archaea/química , Archaea/fisiologia , Extremófilos/química , Extremófilos/fisiologia , Lipídeos de Membrana/química , Aclimatação/fisiologia , Ambientes Extremos , Temperatura Alta , Bicamadas Lipídicas/química , Fluidez de Membrana , Lipídeos de Membrana/síntese química , Modelos Moleculares , Estrutura Molecular , Difração de Nêutrons , Permeabilidade , Pressão , Espalhamento a Baixo Ângulo , Espectrometria de Fluorescência , Esqualeno/análogos & derivados , Esqualeno/química , Terpenos/química , Difração de Raios X
7.
Public Health Nurs ; 38(5): 850-855, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34110634

RESUMO

In this library-nursing initiative, the goal was to identify any changes in stigmatic perceptions among public library staff regarding mental health and substance abuse, post 3-day educational sessions. A total of n = 37 library staff participated in this project and attended all three educational sessions and completed a pre- and postquestionnaire designed to address common mental health and substance abuse-related stigmatic perceptions among public library staff. Upon analysis of the pre- and postresponses, we identified that there were statistically significant changes in two perceptions, namely; "embarrassed to disclose mental illness" and "commonality of substance abuse" (p ≤ .05). Therefore, it is essential that behavioral health nurses engage and collaborate with local public libraries to educate and build a safe environment for vulnerable populations like those affected with mental illness and substance abuse in the community settings.

8.
J Neurosci ; 41(31): 6714-6725, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34183446

RESUMO

An indispensable feature of episodic memory is our ability to temporally piece together different elements of an experience into a coherent memory. Hippocampal time cells-neurons that represent temporal information-may play a critical role in this process. Although these cells have been repeatedly found in rodents, it is still unclear to what extent similar temporal selectivity exists in the human hippocampus. Here, we show that temporal context modulates the firing activity of human hippocampal neurons during structured temporal experiences. We recorded neuronal activity in the human brain while patients of either sex learned predictable sequences of pictures. We report that human time cells fire at successive moments in this task. Furthermore, time cells also signaled inherently changing temporal contexts during empty 10 s gap periods between trials while participants waited for the task to resume. Finally, population activity allowed for decoding temporal epoch identity, both during sequence learning and during the gap periods. These findings suggest that human hippocampal neurons could play an essential role in temporally organizing distinct moments of an experience in episodic memory.SIGNIFICANCE STATEMENT Episodic memory refers to our ability to remember the what, where, and when of a past experience. Representing time is an important component of this form of memory. Here, we show that neurons in the human hippocampus represent temporal information. This temporal signature was observed both when participants were actively engaged in a memory task, as well as during 10-s-long gaps when they were asked to wait before performing the task. Furthermore, the activity of the population of hippocampal cells allowed for decoding one temporal epoch from another. These results suggest a robust representation of time in the human hippocampus.


Assuntos
Hipocampo/fisiologia , Memória Episódica , Neurônios/fisiologia , Percepção do Tempo/fisiologia , Adulto , Eletrocorticografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Front Chem ; 8: 594039, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33282836

RESUMO

Archaea are known to inhabit some of the most extreme environments on Earth. The ability of archaea possessing membrane bilayers to adapt to high temperature (>85°C) and high pressure (>1,000 bar) environments is proposed to be due to the presence of apolar polyisoprenoids at the midplane of the bilayer. In this work, we study the response of this novel membrane architecture to both high temperature and high hydrostatic pressure using neutron diffraction. A mixture of two diether, phytanyl chain lipids (DoPhPC and DoPhPE) and squalane was used to model this novel architecture. Diffraction data indicate that at high temperatures a stable coexistence of fluid lamellar phases exists within the membrane and that stable coexistence of these phases is also possible at high pressure. Increasing the amount of squalane in the membrane regulates the phase separation with respect to both temperature and pressure, and also leads to an increase in the lamellar repeat spacing. The ability of squalane to regulate the ultrastructure of an archaea-like membrane at high pressure and temperature supports the hypothesis that archaea can use apolar lipids as an adaptive mechanism to extreme conditions.

10.
Biomolecules ; 10(12)2020 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322722

RESUMO

The enzyme model, mouse acetylcholinesterase, which exhibits its active site at the bottom of a narrow gorge, was investigated in the presence of different concentrations of sucrose to shed light on the protein and water dynamics in cholinesterases. The study was conducted by incoherent neutron scattering, giving access to molecular dynamics within the time scale of sub-nano to nanoseconds, in comparison with molecular dynamics simulations. With increasing sucrose concentration, we found non-linear effects, e.g., first a decrease in the dynamics at 5 wt% followed by a gain at 10 wt% sucrose. Direct comparisons with simulations permitted us to understand the following findings: at 5 wt%, sugar molecules interact with the protein surface through water molecules and damp the motions to reduce the overall protein mobility, although the motions inside the gorge are enhanced due to water depletion. When going to 10 wt% of sucrose, some water molecules at the protein surface are replaced by sugar molecules. By penetrating the protein surface, they disrupt some of the intra-protein contacts, and induce new ones, creating new pathways for correlated motions, and therefore, increasing the dynamics. This exhaustive study allowed for an explanation of the detail interactions leading to the observed non-linear behavior.


Assuntos
Acetilcolinesterase/metabolismo , Simulação de Dinâmica Molecular , Osmose , Sacarose/farmacologia , Acetilcolinesterase/química , Animais , Camundongos , Nêutrons , Temperatura
11.
Langmuir ; 36(45): 13516-13526, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33146533

RESUMO

Origin of life scenarios generally assume an onset of cell formation in terrestrial hot springs or in the deep oceans close to hot vents, where energy was available for non-enzymatic reactions. Membranes of the protocells had therefore to withstand extreme conditions different from what is found on the Earth surface today. We present here an exhaustive study of temperature stability up to 80 °C of vesicles formed by a mixture of short-chain fatty acids and alcohols, which are plausible candidates for membranes permitting the compartmentalization of protocells. We confirm that the presence of alcohol has a strong structuring and stabilizing impact on the lamellar structures. Moreover and most importantly, at a high temperature (> 60 °C), we observe a conformational transition in the vesicles, which results from vesicular fusion. Because all the most likely environments for the origin of life involve high temperatures, our results imply the need to take into account such a transition and its effect when studying the behavior of a protomembrane model.

13.
Langmuir ; 36(26): 7375-7382, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32515591

RESUMO

Archaea synthesize methyl-branched, ether phospholipids, which confer the archaeal membrane exceptional physicochemical properties. A novel membrane organization was proposed recently to explain the thermal and high pressure tolerance of the polyextremophilic archaeon Thermococcus barophilus. According to this theoretical model, apolar molecules could populate the midplane of the bilayer and could alter the physicochemical properties of the membrane, among which is the possibility to form membrane domains. We tested this hypothesis using neutron diffraction on a model archaeal membrane composed of two archaeal diether lipids with phosphocholine and phosphoethanolamine headgroups in the presence of the apolar polyisoprenoid squalane. We show that squalane is inserted in the midplane at a maximal concentration between 5 and 10 mol % and that squalane can modify the lateral organization of the membrane and induces the coexistence of separate phases. The lateral reorganization is temperature- and squalane concentration-dependent and could be due to the release of lipid chain frustration and the induction of a negative curvature in the lipids.


Assuntos
Archaea , Bicamadas Lipídicas , Fosfolipídeos , Esqualeno/análogos & derivados
14.
Sci Rep ; 10(1): 8265, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427943

RESUMO

Bacterial spores are among the most resistant forms of life on Earth. Their exceptional resistance properties rely on various strategies, among them the core singular structure, organization and hydration. By using elastic incoherent neutron scattering, we probed the dynamics of Bacillus subtilis spores to determine whether core macromolecular motions at the sub-nanosecond timescale could also contribute to their resistance to physical stresses. In addition, in order to better specify the role of the various spore components, we used different mutants lacking essential structure such as the coat (PS4150 mutant), or the calcium dipicolinic acid complex (CaDPA) located in the core (FB122 mutant). PS4150 allows to better probe the core's dynamics, as proteins of the coat represent an important part of spore proteins, and FB122 gives information about the role of the large CaDPA depot for the mobility of core's components. We show that core's macromolecular mobility is not particularly constrained at the sub-nanosecond timescale in spite of its low water content as some dynamical characteristics as force constants are very close to those of vegetative bacteria such as Escherichia coli or to those of fully hydrated proteins. Although the force constants of the coatless mutant are similar to the wild-type's ones, it has lower mean square displacements (MSDs) at high Q showing that core macromolecules are somewhat more constrained than the rest of spore components. However, no behavior reflecting the glassy state regularly evoked in the literature could be drawn from our data. As hydration and macromolecules' mobility are highly correlated, the previous assumption, that core low water content might explain spores' exceptional resistance properties seems unlikely. Thus, we confirm recent theories, suggesting that core water is mostly as free as bulk water and proteins/macromolecules are fully hydrated. The germination of spores leads to a much less stable system with a force constant of 0.1 N/m and MSDs ~2.5 times higher at low Q than in the dormant state. DPA has also an influence on core mobility with a slightly lower force constant for the DPA-less mutant than for the wild-type, and MSDs that are ~ 1.8 times higher on average than for the wild-type at low Q. At high Q, germinated and DPA-less spores were very similar to the wild-type ones, showing that DPA and core compact structure might influence large amplitude motions rather than local dynamics of macromolecules.


Assuntos
Bacillus subtilis/crescimento & desenvolvimento , Ácidos Picolínicos/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Bacillus subtilis/química , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Cinética , Mutação , Esporos Bacterianos/química , Esporos Bacterianos/crescimento & desenvolvimento
15.
Phys Rev E ; 101(3-1): 032415, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32289905

RESUMO

We present a study comparing atomic motional amplitudes in calcium rich and depleted alpha-lactalbumin. The investigations were performed by elastic incoherent neutron scattering (EINS) and molecular dynamics (MD) simulations. As the variations were expected to be very small, three different hydration levels and timescales (instrumental resolutions) were measured. In addition, we used two models to extract the mean square displacements (MSDs) from the EINS data, one taking into account the motional heterogeneity of the MSD. At a timescale of several nanoseconds, small differences in the amplitudes between the calcium enriched and depleted alpha-lactalbumin are visible, whereas at lower timescales no changes can be concluded within the statistics. The results are compared to MD simulations at 280 and 300 K by extracting the MSDs of the trajectories in two separate ways: first by direct calculation, and second by a virtual neutron experiment using the same models as for the experimental data. We show that the simulated data give qualitatively similar results as the experimental data but quantitatively there are differences. Furthermore, the distribution of the MSDs in the simulations suggests that the inclusion of heterogeneity is reasonable for alpha-lactalbumin, but a bi-or trimodal approach may be sufficient.

16.
Int J Mol Sci ; 21(5)2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32155764

RESUMO

Archaea, the most extremophilic domain of life, contain ether and branched lipids which provide extraordinary bilayer properties. We determined the structural characteristics of diether archaeal-like phospholipids as functions of hydration and temperature by neutron diffraction. Hydration and temperature are both crucial parameters for the self-assembly and physicochemical properties of lipid bilayers. In this study, we detected non-lamellar phases of archaeal-like lipids at low hydration levels, and lamellar phases at levels of 90% relative humidity or more exclusively. Moreover, at 90% relative humidity, a phase transition between two lamellar phases was discernible. At full hydration, lamellar phases were present up to 70ᵒC and no phase transition was observed within the temperature range studied (from 25 °C to 70 °C). In addition, we determined the neutron scattering length density and the bilayer's structural parameters from different hydration and temperature conditions. At the highest levels of hydration, the system exhibited rearrangements on its corresponding hydrophobic region. Furthermore, the water uptake of the lipids examined was remarkably high. We discuss the effect of ether linkages and branched lipids on the exceptional characteristics of archaeal phospholipids.


Assuntos
Archaea/fisiologia , Bicamadas Lipídicas/química , Transição de Fase , Fosfolipídeos/química , Temperatura , Água/metabolismo , Difração de Nêutrons
17.
J Psychosoc Nurs Ment Health Serv ; 58(2): 21-26, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32003861

RESUMO

The purpose of this non-experimental descriptive study was to measure psychiatric clinical nurses' (N = 25) perceptions of the Edmonson Psychiatric Falls Risk Assessment Tool© (EPFRAT) compared to the Morse Fall Scale (MFS) and to evaluate patient falls with injury rates 12 months before and after the study. The setting was a 27-bed, adult psychiatric unit in a community-based teaching hospital located in the Northeast region of the United States. The EPFRAT and MFS were used to assess fall risk in 216 patients over 3 months. Findings indicated that the EPFRAT was more user-friendly and relevant; improved nurses' clinical judgment in identifying high-risk patients; and nurses were supportive toward changing practice from using the MFS to EPFRAT for fall risk assessment. Falls with injury rates decreased by 0.52 per 1,000 patient care days post-implementation of the EPFRAT. [Journal of Psychosocial Nursing and Mental Health Services, 58(2), 21-26.].


Assuntos
Acidentes por Quedas , Recursos Humanos de Enfermagem no Hospital/psicologia , Valor Preditivo dos Testes , Unidade Hospitalar de Psiquiatria , Medição de Risco , Acidentes por Quedas/prevenção & controle , Acidentes por Quedas/estatística & dados numéricos , Adulto , Competência Clínica , Feminino , Humanos , Pacientes Internados , Masculino , Enfermagem Psiquiátrica , Estudos Retrospectivos , Estados Unidos
18.
Biomolecules ; 10(1)2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31936876

RESUMO

Lipoproteins are supramolecular assemblies of proteins and lipids with dynamic characteristics critically linked to their biological functions as plasma lipid transporters and lipid exchangers. Among them, spherical high-density lipoproteins are the most abundant forms of high-density lipoprotein (HDL) in human plasma, active participants in reverse cholesterol transport, and associated with reduced development of atherosclerosis. Here, we employed elastic incoherent neutron scattering (EINS) and hydrogen-deuterium exchange mass spectrometry (HDX-MS) to determine the average particle dynamics and protein backbone local mobility of physiologically competent discoidal and spherical HDL particles reconstituted with human apolipoprotein A-I (apoA-I). Our EINS measurements indicated that discoidal HDL was more dynamic than spherical HDL at ambient temperatures, in agreement with their lipid-protein composition. Combining small-angle neutron scattering (SANS) with contrast variation and MS cross-linking, we showed earlier that the most likely organization of the three apolipoprotein A-I (apoA-I) chains in spherical HDL is a combination of a hairpin monomer and a helical antiparallel dimer. Here, we corroborated those findings with kinetic studies, employing hydrogen-deuterium exchange mass spectrometry (HDX-MS). Many overlapping apoA-I digested peptides exhibited bimodal HDX kinetics behavior, suggesting that apoA-I regions with the same amino acid composition located on different apoA-I chains had different conformations and/or interaction environments.


Assuntos
Apolipoproteína A-I/química , Lipoproteínas HDL/química , Medição da Troca de Deutério , Humanos , Cinética , Espectrometria de Massas , Modelos Moleculares , Difração de Nêutrons , Conformação Proteica , Multimerização Proteica , Espalhamento a Baixo Ângulo
19.
Commun Biol ; 3(1): 40, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969657

RESUMO

Despite growing interest, the causal mechanisms underlying human neural network dynamics remain elusive. Transcranial Magnetic Stimulation (TMS) allows to noninvasively probe neural excitability, while concurrent fMRI can log the induced activity propagation through connected network nodes. However, this approach ignores ongoing oscillatory fluctuations which strongly affect network excitability and concomitant behavior. Here, we show that concurrent TMS-EEG-fMRI enables precise and direct monitoring of causal dependencies between oscillatory states and signal propagation throughout cortico-subcortical networks. To demonstrate the utility of this multimodal triad, we assessed how pre-TMS EEG power fluctuations influenced motor network activations induced by subthreshold TMS to right dorsal premotor cortex. In participants with adequate motor network reactivity, strong pre-TMS alpha power reduced TMS-evoked hemodynamic activations throughout the bilateral cortico-subcortical motor system (including striatum and thalamus), suggesting shunted network connectivity. Concurrent TMS-EEG-fMRI opens an exciting noninvasive avenue of subject-tailored network research into dynamic cognitive circuits and their dysfunction.


Assuntos
Mapeamento Encefálico , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Eletroencefalografia , Imageamento por Ressonância Magnética , Vias Neurais , Estimulação Magnética Transcraniana , Adulto , Mapeamento Encefálico/métodos , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Feminino , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiologia , Reprodutibilidade dos Testes , Transdução de Sinais , Estimulação Magnética Transcraniana/métodos
20.
Neuroimage ; 204: 116201, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31541697

RESUMO

How are tactile sensations in the breast represented in the female and male brain? Using ultra high-field 7 T MRI in ten females and ten males, we demonstrate that the representation of tactile breast information shows a somatotopic organization, with cortical magnification of the nipple. Furthermore, we show that the core representation of the breast is organized according to the specific nerve architecture that underlies breast sensation, where the medial and lateral sides of one breast are asymmetrically represented in bilateral primary somatosensory cortex. Finally, gradual selectivity signatures allude to a somatotopic organization of the breast area with overlapping, but distinctive, cortical representations of breast segments. Our univariate and multivariate analyses consistently showed similar somatosensory breast representations in males and females. The findings can guide future research on neuroplastic reorganization of the breast area, across reproductive life stages, and after breast surgery.


Assuntos
Mapeamento Encefálico , Mama/fisiologia , Córtex Somatossensorial/fisiologia , Percepção do Tato/fisiologia , Tato/fisiologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
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