scholarly journals The Optogenetic Revolution in Cerebellar Investigations

2020 ◽  
Vol 21 (7) ◽  
pp. 2494
Author(s):  
Francesca Prestori ◽  
Ileana Montagna ◽  
Egidio D’Angelo ◽  
Lisa Mapelli
Keyword(s):  
Stroke Rehabilitation ◽  
Motor Behavior ◽  
Methodological Approach ◽  
Cell Activity ◽  
The Past ◽  
Single Cell Activity ◽  
Neuronal Types ◽  
New Perspective ◽  
High Degree

The cerebellum is most renowned for its role in sensorimotor control and coordination, but a growing number of anatomical and physiological studies are demonstrating its deep involvement in cognitive and emotional functions. Recently, the development and refinement of optogenetic techniques boosted research in the cerebellar field and, impressively, revolutionized the methodological approach and endowed the investigations with entirely new capabilities. This translated into a significant improvement in the data acquired for sensorimotor tests, allowing one to correlate single-cell activity with motor behavior to the extent of determining the role of single neuronal types and single connection pathways in controlling precise aspects of movement kinematics. These levels of specificity in correlating neuronal activity to behavior could not be achieved in the past, when electrical and pharmacological stimulations were the only available experimental tools. The application of optogenetics to the investigation of the cerebellar role in higher-order and cognitive functions, which involves a high degree of connectivity with multiple brain areas, has been even more significant. It is possible that, in this field, optogenetics has changed the game, and the number of investigations using optogenetics to study the cerebellar role in non-sensorimotor functions in awake animals is growing. The main issues addressed by these studies are the cerebellar role in epilepsy (through connections to the hippocampus and the temporal lobe), schizophrenia and cognition, working memory for decision making, and social behavior. It is also worth noting that optogenetics opened a new perspective for cerebellar neurostimulation in patients (e.g., for epilepsy treatment and stroke rehabilitation), promising unprecedented specificity in the targeted pathways that could be either activated or inhibited.

scholarly journals Visualization is crucial for understanding microbial processes in the ocean

2019 ◽  
Vol 374 (1786) ◽  
pp. 20190083 ◽  
Author(s):  
Marta Sebastián ◽  
Josep M. Gasol
Keyword(s):  
Single Cell ◽  
Metabolic Activity ◽  
Cell Activity ◽  
Level Of Activity ◽  
Single Cell Activity ◽  
Recent Developments ◽  
Insight Into ◽  
Do So

Recent developments in community and single-cell genomic approaches have provided an unprecedented amount of information on the ecology of microbes in the aquatic environment. However, linkages between each specific microbe's identity and their in situ level of activity (be it growth, division or just metabolic activity) are much more scarce. The ultimate goal of marine microbial ecology is to understand how the environment determines the types of different microbes in nature, their function, morphology and cell-to-cell interactions and to do so we should gather three levels of information, the genomic (including identity), the functional (activity or growth), and the morphological, and for as many individual cells as possible. We present a brief overview of methodologies applied to address single-cell activity in marine prokaryotes, together with a discussion of the difficulties in identifying and categorizing activity and growth. We then provide and discuss some examples showing how visualization has been pivotal for challenging established paradigms and for understanding the role of microbes in the environment, unveiling processes and interactions that otherwise would have been overlooked. We conclude by stating that more effort should be directed towards integrating visualization in future approaches if we want to gain a comprehensive insight into how microbes contribute to the functioning of ecosystems. This article is part of a discussion meeting issue ‘Single cell ecology’.

scholarly journals Neuronal circuits overcome imbalance in excitation and inhibition by adjusting connection numbers

2021 ◽  
Vol 118 (12) ◽  
pp. e2018459118
Author(s):  
Nirit Sukenik ◽  
Oleg Vinogradov ◽  
Eyal Weinreb ◽  
Menahem Segal ◽  
Anna Levina ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Activity ◽  
Network Activity ◽  
Neuronal Circuitry ◽  
Inhibitory Cell ◽  
Single Cell Activity ◽  
Hippocampal Cultures ◽  
Cell Fractions ◽  
The Brain

The interplay between excitation and inhibition is crucial for neuronal circuitry in the brain. Inhibitory cell fractions in the neocortex and hippocampus are typically maintained at 15 to 30%, which is assumed to be important for stable dynamics. We have studied systematically the role of precisely controlled excitatory/inhibitory (E/I) cellular ratios on network activity using mice hippocampal cultures. Surprisingly, networks with varying E/I ratios maintain stable bursting dynamics. Interburst intervals remain constant for most ratios, except in the extremes of 0 to 10% and 90 to 100% inhibitory cells. Single-cell recordings and modeling suggest that networks adapt to chronic alterations of E/I compositions by balancing E/I connectivity. Gradual blockade of inhibition substantiates the agreement between the model and experiment and defines its limits. Combining measurements of population and single-cell activity with theoretical modeling, we provide a clearer picture of how E/I balance is preserved and where it fails in living neuronal networks.

scholarly journals The journey of Claire in the works of Gaito Gazdanov: the analysis of the female image of Claire in the novels “An Evening with Claire”, “Hannah”, and “The Fate of Salome”

Litera ◽  
2021 ◽  
pp. 162-170
Author(s):  
Ziwei Zhu
Keyword(s):  
Real World ◽  
The Novel ◽  
The Past ◽  
Character Type ◽  
Female Image ◽  
Different Types ◽  
Inner World ◽  
New Perspective ◽  
Gradual Transformation

  This article is dedicated to the analysis of the female image of Claire and its variant in the works of Gaito Gazdanov. This character type in the works of G. Gazdanov often resembles the past in the present, i.e. an important part of the “lost world” for the protagonist. However, deliberate examination allows following the gradual transformation of the authors attitude towards the character of Claire throughout his creative path. In the novel “Ab Evening with Clair”, the author adheres to priority of that past world over the present, while in the novel of his later period “The Fate of Salome”, the narrator tends to release from the shadow of the past. The underlying cause for such change lies in the transition of the writer from the romantic theurgical worldview towards phenomenal. In the later period, Gazdanov reconsidered the real world and justified the earthly existence due to the fact that submerging into the own inner world can entail loneliness and dissolution “Self” in one’s mind. The goal of this research consists in tracing the transformation of the role of Claire in the works of Gaito Gazdanov, as well as in description of different types of relations between the protatonist and the heroine in order to prove the evolution of the writer's reasoning on the problem of “two-worldness”. The relevance of this article consists in explication of the type of Claire in Gazdanov’s artistic system of “two-worldness” as a literary technique, as well as from the new perspective of studying the evolution the writer’s worldview.  

Oral Sources and Social Differentiation in the Jaara Kingdom from the Sixteenth Century: A Methodological Approach

1995 ◽  
Vol 22 ◽  
pp. 123-139
Author(s):  
Mamadou Diawara
Keyword(s):  
Sixteenth Century ◽  
Methodological Approach ◽  
Social Classes ◽  
Social Differentiation ◽  
Oral Literature ◽  
The Public ◽  
The Past ◽  
History Of ◽  
The Subject

The dawn of the history of the kingdom of Jaara, during the era of the Jawara dynasty (from the fifteenth to the mid-nineteenth century) is shaped by the story of Daaman Gille and his companions, the most important of whom is Jonpisugo. The lives of these two characters—linked up until their death at Banbagede, where their tombs are only a few hundred meters apart—were the subject of a rich oral literature, all the more noteworthy given the rarity of written documents.In my earlier work (Diawara 1985, 1989, 1990) I discussed the typology of narratives and the specific role of women servants as historians of their social group. The oral sources include family traditions from all social classes, except for recently acquired slaves; the recitals of professional narrators who were by heredity in the service of protector families whose history they proclaimed to the public; the narratives of servants, including the tanbasire, a collection of women's songs from among the royal servants, or the accounts of people who, with their ancestors, had long been slaves (cf. Diawara 1990).Historical chance brings together Daama and Jonpisugo, but their respective social standing differentiates them; just as “friendship” brings together the master and the servant, so the struggle for power leads to the birth of differences in the conception of “the things of the past” among their descendants. How is the past constructed and lived differently by their respective progeny or supposed descendants? What poetic license accrues to the offspring of he who was only a servant, even if he was a royal servant? The response to this question explains the dynamic of a particular servants' oral documentation.

scholarly journals Antimicrobial Films based on Chitosan, Collagen, and ZnO for Skin Tissue Regeneration

2020 ◽  
Vol 11 (4) ◽  
pp. 11985-11995
Keyword(s):  
Zinc Oxide ◽  
Tissue Regeneration ◽  
Wound Dressing ◽  
Bacterial Infections ◽  
Cell Activity ◽  
The Past ◽  
Major Interest ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Bacterial infections represent a health issue worldwide. Over the past years, major interest has been given to developing new antibacterial and regenerative materials due to the increasing number of infections with pathogenic strains and the alarming antibiotic resistance. Polymer films and membranes with protective or even anti-infectious activity were developed. Some of them were based on nanoparticles with the main advantage that the resistance's development only seldom appears. Considering the Collagenic nature of the skin and the beneficial properties of Chitosan, the two polymers were proposed to be used in developing nanostructured wound dressing loaded with ZnO nanoparticles. These nanostructured materials confer promising characteristics to be used as anti-infectious wound dressing being biocompatible, antimicrobial against C. albicans and S. aureus, and highly hydrophilic able to absorb over 2300% water, which confer the premises of maintaining proper humidity and exudate absorption during wound healing. Fibrillar structures with Chitosan, Collagen, and Zinc Oxide can be an alternative for tissue regeneration. Electrospinning was used to fabricate fibrillar structures consisting of doing Chitosan, Collagen, and Zinc Oxide. The Zinc Oxide was used to defend the wound against infections and the beneficial role of Zn2+ in enhancing cell activity. The morphology of the fibrillar structures was studied by scanning electron microscopy while Collagen integrity by FT-IR spectroscopy.

scholarly journals Purkinje Cell Representations of Behavior: Diary of a Busy Neuron

2018 ◽  
Vol 25 (3) ◽  
pp. 241-257 ◽  
Author(s):  
Laurentiu S. Popa ◽  
Martha L. Streng ◽  
Timothy J. Ebner
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Motor Behavior ◽  
Cell Activity ◽  
Computational Framework ◽  
Simple Spike ◽  
Cerebellar Function ◽  
Performance Error ◽  
And Performance ◽  
High Degree

Fundamental for understanding cerebellar function is determining the representations in Purkinje cell activity, the sole output of the cerebellar cortex. Up to the present, the most accurate descriptions of the information encoded by Purkinje cells were obtained in the context of motor behavior and reveal a high degree of heterogeneity of kinematic and performance error signals encoded. The most productive framework for organizing Purkinje cell firing representations is provided by the forward internal model hypothesis. Direct tests of this hypothesis show that individual Purkinje cells encode two different forward models simultaneously, one for effector kinematics and one for task performance. Newer results demonstrate that the timing of simple spike encoding of motor parameters spans an extend interval of up to ±2 seconds. Furthermore, complex spike discharge is not limited to signaling errors, can be predictive, and dynamically controls the information in the simple spike firing to meet the demands of upcoming behavior. These rich, diverse, and changing representations highlight the integrative aspects of cerebellar function and offer the opportunity to generalize the cerebellar computational framework over both motor and non-motor domains.

scholarly journals Agenciamiento de la memoria social en la escuela colombiana como mecanismo reparador

2017 ◽  
pp. 171-204
Author(s):  
Ingrid Lorena Torres Gámez
Keyword(s):  
Social Sciences ◽  
Exponential Growth ◽  
Armed Conflict ◽  
Social Memory ◽  
Methodological Approach ◽  
The Past ◽  
The Social

El presente trabajo tiene como principal objetivo reflexionar sobre el papel de la escue­la en los ejercicios de reparación de afectaciones acaecidas en el marco del conflicto armado en Colombia. Para dicha tarea, resulta importante reconocer que hace aproximadamente tres décadas las Ciencias Sociales asisten al crecimiento exponencial de trabajos que sitúan la memoria como elemento sustancial en la comprensión del pasado y su incidencia en los discursos sociales, polí­ticos, culturales y normativos del presente, frente a los cuales la escuela no es indiferente, pues se encuentra en un lugar privilegiado para la producción y reproducción de discursos relacionados con los ejercicios de memoria. En este sentido, se acude metodológicamente al orden cualitativo de revisión bibliográfica, enfatizada en la localización y recuperación de información para construir reflexiones desde la óptica de la pedagogía de la memoria, que, más que conclusiones, se conciben como abrebocas ante la mirada multidisciplinar con la que es necesario asumir los retos del reco­nocimiento de las diversas formas de reparar en la escuela.Palabras clave: memoria social, conflicto armado, escuela, reparación. ABSTRACTSocial memory agency in the Colombian school as a reparation mechanism The aim of this article is to reflect on the role of the school in the exercises for making amends that have occurred in the context of the armed conflict in Colombia. For this task, it is important to recognize that approximately three decades ago Social Sciences attended the exponential growth of works that place the memory as a substantial element in the understanding of the past and its incidence in the social, political, cultural and normative discourses of the present, in which the school is not indifferent, because it is on a privileged place for the production and reproduction of discourses related to memory exer­cises. In this sense, a methodological approach is done tothe qualitative order of bibliographic review, emphasized in the location and retrieval of information, to build reflections from the perspective of the pedagogy of memory, which, more than conclusions, are conceived as an appetizer before the multidisciplinary view that is necessary to assume the challenges of the recognition of the diverse forms to make amend for the school.Keywords: social memory, armed conflict, school, to make amend for.

Purified Rubber for Electrical Insulation

1937 ◽  
Vol 10 (3) ◽  
pp. 474-491
Author(s):  
A. R. Kemp
Keyword(s):  
Water Absorption ◽  
Far East ◽  
Electrical Stability ◽  
The Past ◽  
The Far East ◽  
Other Substances ◽  
Moisture Conditions ◽  
High Degree ◽  
Soft Rubber

Abstract THE water absorption and the dielectric stability of soft rubber insulating compounds under wet conditions is influenced by the kind of crude rubber employed. For most rubber-covered aerial and building wire where moisture conditions are not severe, the better grades of plantation rubber are satisfactory. However, for service involving immersion for long periods in fresh water, a need exists for rubber containing less nonhydrocarbon water-absorbing substances than the plantation product. This is particularly true when the insulating wall is thin and a high degree of electrical stability is required. Only recently has the preparation of such a type of purified rubber been given serious consideration on the plantations in the Far East. In the past, coöperation on such a problem with the plantation has been difficult, and for that and other reasons methods have been developed here for preparing this rubber in the factory. The purpose of this paper is to discuss the nature and role of protein and other substances found in Hevea rubber and to outline various methods for purifying rubber. Data are presented on the composition and properties of the resulting products.

Re-Membering

2016 ◽  
Author(s):  
Roy Suddaby ◽  
William Foster ◽  
Christine Quinn Trank
Keyword(s):  
Identity Work ◽  
Focused Attention ◽  
Rhetorical History ◽  
The Past ◽  
Identity Narratives ◽  
Critical Resource ◽  
Historical Identity ◽  
High Degree ◽  
The Relationship

We explore and extend an emerging interest in understanding the relationship between language and history in organizational identity work. Recent research has focused attention on the role of “temporal talk” in creating identity—that is, how discourse about the past, present, and future constructs identification. These studies understate the degree of agency in temporal talk and fail to capture the importance of history as a competitive resource. We introduce the term “rhetorical history” to draw attention to the high degree of deliberate and strategic use of persuasive language to construct historical identity narratives in corporations. We also elaborate the understanding, within organizations, of history as critical resource that can be deployed to manage membership with a broad range of organizational stakeholders.

scholarly journals TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis

2012 ◽  
Vol 2012 ◽  
pp. 1-29 ◽  
Author(s):  
Johannes W. Dietrich ◽  
Gabi Landgrafe ◽  
Elisavet H. Fotiadou
Keyword(s):  
Dynamic Behaviour ◽  
Reference Range ◽  
Current Knowledge ◽  
Epidemiological Investigation ◽  
Mathematical Methods ◽  
Systems Perspective ◽  
The Past ◽  
New Perspective ◽  
Critical Components

This paper provides the reader with an overview of our current knowledge of hypothalamic-pituitary-thyroid feedback from a cybernetic standpoint. Over the past decades we have gained a plethora of information from biochemical, clinical, and epidemiological investigation, especially on the role of TSH and other thyrotropic agonists as critical components of this complex relationship. Integrating these data into a systems perspective delivers new insights into static and dynamic behaviour of thyroid homeostasis. Explicit usage of this information with mathematical methods promises to deliver a better understanding of thyrotropic feedback control and new options for personalised diagnosis of thyroid dysfunction and targeted therapy, also by permitting a new perspective on the conundrum of the TSH reference range.

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