Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Acta Biomater ; 158: 292-307, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36632879

RESUMO

The multicellular inflammatory encapsulation of implanted intracortical multielectrode arrays (MEA) is associated with severe deterioration of their field potentials' (FP) recording performance, which thus limits the use of brain implants in basic research and clinical applications. Therefore, extensive efforts have been made to identify the conditions in which the inflammatory foreign body response (FBR) is alleviated, or to develop methods to mitigate the formation of the inflammatory barrier. Here, for the first time, we show that (1) in young rats (74±8 gr, 4 weeks old at the onset of the experiments), cortical tissue recovery following MEA implantation proceeds with ameliorated inflammatory scar as compared to adult rats (242 ± 18 gr, 9 weeks old at the experimental onset); (2) in contrast to adult rats in which the Colony Stimulating factor 1 Receptor (CSF1R) antagonist chow eliminated ∼95% of the cortical microglia but not microglia adhering to the implant surfaces, in young rats the microglia adhering to the implant were eliminated along with the parenchymal microglia population. The removal of microglia adhering to the implant surfaces was correlated with improved recording performance by in-house fabricated Perforated Polyimide MEA Platforms (PPMP). These results support the hypothesis that microglia adhering to the surface of the electrodes, rather than the multicellular inflammatory scar, is the major underlying mechanism that deteriorates implant recording performance, and that young rats provide an advantageous model to study months-long, multisite electrophysiology in freely behaving rats. STATEMENT OF SIGNIFICANCE: Multisite electrophysiological recordings and stimulation devices play central roles in basic brain research and medical applications. The insertion of multielectrode-array platforms into the brain's parenchyma unavoidably injures the tissue, and initiates a multicellular inflammatory cascade culminating in the formation of an encapsulating scar tissue (the foreign body response-FBR). The dominant view, which directs most current research efforts to mitigate the FBR, holds that the FBR is the major hurdle to effective electrophysiological use of neuroprobes. By contrast, this report demonstrates that microglia adhering to the surface of a neuroimplants, rather than the multicellular FBR, underlie the performance deterioration of neuroimplants. These findings pave the way to the development of novel and focused strategies to overcome the functional deterioration of neuroimplants.


Assuntos
Encéfalo , Reação a Corpo Estranho , Próteses Neurais , Animais , Ratos , Encéfalo/patologia , Encéfalo/cirurgia , Cicatriz/patologia , Reação a Corpo Estranho/patologia , Próteses Neurais/efeitos adversos , Fatores Etários
2.
Pharmaceuticals (Basel) ; 15(5)2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35631395

RESUMO

Microglia play pivotal roles in central nervous system development, homeostasis, responses to trauma, and neurodegenerative and neuropsychiatric disorders with significant sex-bias in their symptoms and prevalence. Survival of the microglia in adult brains depends on the expression of the colony-stimulating factor 1 receptor (CSF1R). The inhibition of CSF1R by brain-permeant PLX5622 in the chow eliminates, within 5-10 days, ~90% of the microglia in female and male mice, thereby enabling the investigation of the roles of the microglia in health and pathological mice models. Because of a prevailing "impression" that PLX5622 is ineffective in rats, it has hardly been used in studies of adult rats. Here, we report that effective microglia elimination by PLX5622-chow in rats is highly sex-dependent. Our observations provide missing information for the limited use and interpretation of PLX5622 in biomedical studies of the microglia in rat models. The sex differences that are too often overlooked must be carefully considered and clearly emphasized.

3.
Public Underst Sci ; 31(1): 2-18, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34250852

RESUMO

The Internet has potential to alleviate inequality in general and specifically with respect to science literacy. Nevertheless, digital divides persist in online access and use, as well as in subsequent social outcomes. Among these, the "language divide" partly determines how successful users are in their Internet use depending on their proficiency in languages, and especially in English. To examine whether the quality of online scientific information varies between languages when conducting searches from the same country, we compared online search results regarding scientific terms in English, Hebrew, and Arabic. Findings indicate that searches in English yielded overall higher quality results, compared with Hebrew and Arabic, but mostly in pedagogical aspects, rather than scientific ones. Clustering the results by language yielded better separation than clustering by scientific field, pointing to a "language divide" in access to online science content. We argue that scientific communities and institutions should mitigate this language divide.1.


Assuntos
Internet , Idioma
4.
Front Neurosci ; 15: 764448, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34880722

RESUMO

Despite increasing use of in vivo multielectrode array (MEA) implants for basic research and medical applications, the critical structural interfaces formed between the implants and the brain parenchyma, remain elusive. Prevailing view assumes that formation of multicellular inflammatory encapsulating-scar around the implants [the foreign body response (FBR)] degrades the implant electrophysiological functions. Using gold mushroom shaped microelectrodes (gMµEs) based perforated polyimide MEA platforms (PPMPs) that in contrast to standard probes can be thin sectioned along with the interfacing parenchyma; we examined here for the first time the interfaces formed between brains parenchyma and implanted 3D vertical microelectrode platforms at the ultrastructural level. Our study demonstrates remarkable regenerative processes including neuritogenesis, axon myelination, synapse formation and capillaries regrowth in contact and around the implant. In parallel, we document that individual microglia adhere tightly and engulf the gMµEs. Modeling of the formed microglia-electrode junctions suggest that this configuration suffice to account for the low and deteriorating recording qualities of in vivo MEA implants. These observations help define the anticipated hurdles to adapting the advantageous 3D in vitro vertical-electrode technologies to in vivo settings, and suggest that improving the recording qualities and durability of planar or 3D in vivo electrode implants will require developing approaches to eliminate the insulating microglia junctions.

5.
Educ Stud Math ; 108(1-2): 201-225, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34934235

RESUMO

In the first months of 2020, as the COVID-19 pandemic became a top concern worldwide, media coverage became full of information that demands mathematical literacy, or numeracy, to interpret. In this study, we examine the public's understanding of mathematical notions that are required for understanding the pandemic and predicting its spread. We also explore its correlations with several variables: age group and gender, educational attainment in mathematics, and mathematics identity. To do so, we conducted a cross-sectional survey focusing on mathematical knowledge relevant to the pandemic. The survey was distributed to a representative sample of the Jewish Israeli population (n = 439). Findings showed that participants' educational attainment in mathematics was positively correlated with their success in the mathematical media literacy tasks. However, even those with high attainment levels did not always perform well. Moreover, the explanatory variable with the strongest relationship to mathematical media literacy was found to be participants' mathematical identity. These results suggest that school mathematics, especially in its high levels, may prepare adults to understand critical information important for their well-being, such as at a time of global pandemic. However, they also demonstrate that a weak mathematical identity may significantly hinder adults' engagement with such information. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10649-021-10075-8.

6.
Front Neurosci ; 15: 646914, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841088

RESUMO

Inflammatory encapsulation of implanted cortical-neuro-probes [the foreign body response (FBR)] severely limits their use in basic brain research and in clinical applications. A better understanding of the inflammatory FBR is needed to effectively mitigate these critical limitations. Combining the use of the brain permeant colony stimulating factor 1 receptor inhibitor PLX5622 and a perforated polyimide-based multielectrode array platform (PPMP) that can be sectioned along with the surrounding tissue, we examined the contribution of microglia to the formation of inflammatory FBR. To that end, we imaged the inflammatory processes induced by PPMP implantations after eliminating 89-94% of the cortical microglia by PLX5622 treatment. The observations showed that: (I) inflammatory encapsulation of implanted PPMPs proceeds by astrocytes in microglia-free cortices. The activated astrocytes adhered to the PPMP's surfaces. This suggests that the roles of microglia in the FBR might be redundant. (II) PPMP implantation into control or continuously PLX5622-treated rats triggered a localized surge of microglia mitosis. The daughter cells that formed a "cloud" of short-lived (T 1 / 2 ≤ 14 days) microglia around and in contact with the implant surfaces were PLX5622 insensitive. (III) Neuron degeneration by PPMP implantation and the ensuing recovery in time, space, and density progressed in a similar manner in the cortices following 89-94% depletion of microglia. This implies that microglia do not serve a protective role with respect to the neurons. (IV) Although the overall cell composition and dimensions of the encapsulating scar in PLX5622-treated rats differed from the controls, the recorded field potential (FP) qualities and yield were undistinguishable. This is accounted for by assuming that the FP amplitudes in the control and PLX5622-treated rats were related to the seal resistance formed at the interface between the adhering microglia and/or astrocytes and the PPMP platform rather than across the scar tissue. These observations suggest that the prevention of both astrocytes and microglia adhesion to the electrodes is required to improve FP recording quality and yield.

7.
Front Neurosci ; 15: 807797, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35145375

RESUMO

Developing novel neuroprobes that enable parallel multisite, long-term intracellular recording and stimulation of neurons in freely behaving animals is a neuroscientist's dream. When fulfilled, it is expected to significantly enhance brain research at fundamental mechanistic levels including that of subthreshold signaling and computations. Here we assess the feasibility of merging the advantages of in vitro vertical nanopillar technologies that support intracellular recordings with contemporary concepts of in vivo extracellular field potential recordings to generate the dream neuroprobes that read the entire electrophysiological signaling repertoire.

8.
Front Neurosci ; 14: 926, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982683

RESUMO

The deterioration of field potential (FP) recording quality and yield by in vivo multielectrode arrays (MEA) within days to weeks of implantation severely limits progress in basic and applied brain research. The prevailing hypothesis is that implantation of MEA platforms initiate and perpetuate inflammatory processes which culminate in the formation of scar tissue (the foreign body response, FBR) around the implant. The FBR leads to progressive degradation of the recording qualities by displacing neurons away from the electrode surfaces, increasing the resistance between neurons (current source) and the sensing pads and by reducing the neurons' excitable membrane properties and functional synaptic connectivity through the release of pro-inflammatory cytokines. Meticulous attempts to causally relate the cellular composition, cell density, and electrical properties of the FBR have failed to unequivocally correlate the deterioration of recording quality with the histological severity of the FBR. Based on confocal and electron microscope analysis of thin sections of polyimide based MEA implants along with the surrounding brain tissue at different points in time after implantation, we propose that abrupt FP amplitude attenuation occurs at the implant/brain-parenchyma junction as a result of high seal resistance insulation formed by adhering microglia to the implant surfaces. In contrast to the prevailing hypothesis, that FP decrease occurs across the encapsulating scar of the implanted MEA, this mechanism potentially explains why no correlations have been found between the dimensions and density of the FBR and the recording quality. Recognizing that the seal resistance formed by adhering-microglia to the implant constitutes a downstream element undermining extracellular FP recordings, suggests that approaches to mitigate the formation of the insulating glial could lead to improved recording quality and yield.

9.
Vaccine ; 38(12): 2691-2699, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32061384

RESUMO

Experts are concerned about the spread and recalcitrance of vaccine misinformation and its contribution to vaccine hesitancy. Despite this risk, little research attention has been paid to understanding how individuals seek vaccine information online and evaluate its trustworthiness. Here, we hypothesized that when vaccine-hesitant parents seek information about vaccines, they prefer trustworthy sources based on their competence, integrity and benevolence. We explored this issue using 4910 questions and 2583 answers retrieved from two social question-and-answer (Q&A) platforms: "Yahoo! Answers" and the Facebook group "Talking about Vaccines." We examined what kinds of questions are asked about vaccines, to what extent they are explicitly directed at health professionals or parents, and what features of the answers predict perceived answer quality, based on the theory of epistemic trust. The findings indicate that on different platforms, vaccine-related questions focus on different topics; namely, questions on one platform focused on the risks and benefits of vaccination, whereas they dealt with vaccine schedules on the other. On both platforms, most questions did not specify that an answer should be based on professional expertise or parents' experience. Both pro-vaccine and anti-vaccine answers were proportionately represented among the "best answers". However, if an answer was written by a health professional, the askers and the community on "Yahoo! Answers" were twice as likely to choose it as the "best answer" to a vaccine-related question, irrespective of whether it encouraged or discouraged vaccination. By contrast, an online experiment revealed that both the identity of the respondent and the stance towards vaccination affected the perceived trustworthiness of the answers. These findings indicate that despite the proliferation of anti-vaccine messages, epistemic trust in mainstream science and medicine is robust. User responses to expert answers suggest that expert outreach in online environments may be an effective intervention to address vaccine hesitancy.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Comportamento de Busca de Informação , Meios de Comunicação de Massa/estatística & dados numéricos , Pais/psicologia , Confiança/psicologia , Vacinas/uso terapêutico , Compreensão , Humanos , Vacinação/ética
10.
Public Underst Sci ; 29(3): 252-269, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31971072

RESUMO

Social media allow experts to form communities and engage in direct dialogue with publics, which can promote mutual understanding between sciences and publics. However, little is known about experts' participation in online communities, or effective ways to prepare them for public engagement. Here, we explored these issues with experts who voluntarily engage with publics on social media, to understand their public engagement practices. Stimulated recall interviews were conducted with 20 experts who participate in question-and-answer Facebook groups dedicated to vaccines and nutrition. The findings suggest that experts employ diverse considerations in their outreach, partly to establish epistemic trustworthiness. These can be grouped into three goals and two constraints: countering misinformation, establishing benevolence, and establishing competence while maintaining integrity and clarity. Empathic failure and burnout both emerged as factors that impair establishing benevolence. We discuss implications for community-level science literacy and for preparing scientists for "bounded engagement with publics."


Assuntos
Prova Pericial/estatística & dados numéricos , Disseminação de Informação , Ciências da Nutrição , Vacinação , Disseminação de Informação/métodos , Entrevistas como Assunto
11.
Public Underst Sci ; 26(8): 969-985, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-27208006

RESUMO

In response to the news coverage of scientific events and to science education, people increasingly go online to get more information. This study investigates how patterns of science and technology information-seeking on Google and Wikipedia change over time, in ways that differ between "ad hoc" terms that correspond to news coverage and "cyclic" terms that correspond to the academic period. Findings show that the science and technology activity in Google and Wikipedia was significantly associated with ad hoc and cyclic patterns. While the peak activity in Google and Wikipedia largely overlapped for ad hoc terms, it mismatched for cyclic terms. The findings indicate the importance of external cues such as news media and education, and also of the online engagement process, and particularly the crucial but different role played by Google and Wikipedia in gaining science and technology knowledge. Educators and policy makers could benefit from taking into account those different patterns.


Assuntos
Enciclopédias como Assunto , Comportamento de Busca de Informação , Internet , Ciência , Ferramenta de Busca , Participação da Comunidade , Humanos
12.
PLoS One ; 11(5): e0156409, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27232498

RESUMO

Although the scientific community increasingly recognizes that its communication with the public may shape civic engagement with science, few studies have characterized how this communication occurs online. Social media plays a growing role in this engagement, yet it is not known if or how different platforms support different types of engagement. This study sets out to explore how users engage with science communication items on different platforms of social media, and what are the characteristics of the items that tend to attract large numbers of user interactions. Here, user interactions with almost identical items on five of CERN's social media platforms were quantitatively compared over an eight-week period, including likes, comments, shares, click-throughs, and time spent on CERN's site. The most popular items were qualitatively analyzed for content features. Findings indicate that as audience size of a social media platform grows, the total rate of engagement with content tends to grow as well. However, per user, engagement tends to decline with audience size. Across all platforms, similar topics tend to consistently receive high engagement. In particular, awe-inspiring imagery tends to frequently attract high engagement across platforms, independent of newsworthiness. To our knowledge, this study provides the first cross-platform characterization of public engagement with science on social media. Findings, although focused on particle physics, have a multidisciplinary nature; they may serve to benchmark social media analytics for assessing science communication activities in various domains. Evidence-based suggestions for practitioners are also offered.


Assuntos
Participação da Comunidade/psicologia , Física , Mídias Sociais , Prática Clínica Baseada em Evidências , Humanos , Fatores de Tempo
13.
Public Underst Sci ; 23(5): 528-46, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23825277

RESUMO

Leaders of the scientific community encourage scientists to learn effective science communication, including honing the skill to discuss science with little professional jargon. However, avoiding jargon is not trivial for scientists for several reasons, and this demands special attention in teaching and evaluation. Despite this, no standard measurement for the use of scientific jargon in speech has been developed to date. Here a standard yardstick for the use of scientific jargon in spoken texts, using a computational linguistics approach, is proposed. Analyzed transcripts included academic speech, scientific TEDTalks, and communication about the discovery of a Higgs-like boson at CERN. Findings suggest that scientists use less jargon in communication with a general audience than in communication with peers, but not always less obscure jargon. These findings may lay the groundwork for evaluating the use of jargon.


Assuntos
Comunicação , Ciência/educação , Disseminação de Informação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...