Ensheathment and Myelination of Axons: Evolution of Glial Functions

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Klaus-Armin Nave ◽  
Hauke B. Werner

Myelination of axons provides the structural basis for rapid saltatory impulse propagation along vertebrate fiber tracts, a well-established neurophysiological concept. However, myelinating oligodendrocytes and Schwann cells serve additional functions in neuronal energy metabolism that are remarkably similar to those of axon-ensheathing glial cells in unmyelinated invertebrates. Here we discuss myelin evolution and physiological glial functions, beginning with the role of ensheathing glia in preventing ephaptic coupling, axoglial metabolic support, and eliminating oxidative radicals. In both vertebrates and invertebrates, axoglial interactions are bidirectional, serving to regulate cell fate, nerve conduction, and behavioral performance. One key step in the evolution of compact myelin in the vertebrate lineage was the emergence of the open reading frame for myelin basic protein within another gene. Several other proteins were neofunctionalized as myelin constituents and help maintain a healthy nervous system. Myelination in vertebrates became a major prerequisite of inhabiting new ecological niches. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Michael Lounsbury ◽  
Christopher W.J. Steele ◽  
Milo Shaoqing Wang ◽  
Madeline Toubiana

In this article, we take stock of the institutional logics perspective and highlight opportunities for new scholarship. While we celebrate the growth and generativity of the literature on institutional logics, we also note that there has been a troubling tendency in recent work to use logics as analytical tools, feeding disquiet about reification and reductionism. Seeding a broader scholarly agenda that addresses such weaknesses in the literature, we highlight nascent efforts that aim to more systematically understand institutional logics as complex, dynamic phenomena in their own right. In doing so, we argue for more research that probes how logics cohere and endure by unpacking the role of values, the centrality of practice, and the governance dynamics of institutional logics and their orders. Furthermore, we encourage bridging the study of institutional logics with various literatures, including ethnomethodology, phenomenology, professions, elites, world society, and the old institutionalism, to enhance progress in these directions. Expected final online publication date for the Annual Review of Sociology, Volume 47 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Lisa G. Rosas ◽  
Patricia Rodriguez Espinosa ◽  
Felipe Montes Jimenez ◽  
Abby C. King

While there are many definitions of citizen science, the term usually refers to the participation of the general public in the scientific process in collaboration with professional scientists. Citizen scientists have been engaged to promote health equity, especially in the areas of environmental contaminant exposures, physical activity, and healthy eating. Citizen scientists commonly come from communities experiencing health inequities and have collected data using a range of strategies and technologies, such as air sensors, water quality kits, and mobile applications. On the basis of our review, and to advance the field of citizen science to address health equity, we recommend ( a) expanding the focus on topics important for health equity, ( b) increasing the diversity of people serving as citizen scientists, ( c) increasing the integration of citizen scientists in additional research phases, ( d) continuing to leverage emerging technologies that enable citizen scientists to collect data relevant for health equity, and ( e) strengthening the rigor of methods to evaluate impacts on health equity. Expected final online publication date for the Annual Review of Public Health, Volume 43 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Andrew K. Scherer

The mid-1990s through the first decade of the new millennium marked an increase in publications pertaining to war and violence in the ancient past. This review considers how scholars of the past decade have responded to that work. The emerging consensus is that war and violence were endemic to all societies studied by archaeologists, and yet the frequency, intensity, causes, and consequences of violence were highly variable for reasons that defy simplistic explanation. The general trend has been toward archaeologies of war and violence that focus on understanding the nuances of particular places and historical moments. Nevertheless, archaeologists continue to grapple with grand narratives of war, such as the proposition that violence has decreased from ancient to modern times and the role of war and violence in state formation and collapse. Recent research also draws attention to a more expansive definition of violence. Expected final online publication date for the Annual Review of Anthropology, Volume 50 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Masaki Isoda

As a frontal node in the primate social brain, the medial prefrontal cortex (MPFC) plays a critical role in coordinating one's own behavior with respect to that of others. Current literature demonstrates that single neurons in the MPFC encode behavior-related variables such as intentions, actions, and rewards, specifically for self and other, and that the MPFC comes into play when reflecting upon oneself and others. The social moderator account of MPFC function can explain maladaptive social cognition in people with autism spectrum disorder, which tips the balance in favor of self-centered perspectives rather than taking into consideration the perspective of others. Several strands of evidence suggest a hypothesis that the MPFC represents different other mental models, depending on the context at hand, to better predict others’ emotions and behaviors. This hypothesis also accounts for aberrant MPFC activity in autistic individuals while they are mentalizing others. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Christine Schreyer

Constructed languages, also known as conlangs, are languages that have been purposefully created for either real-world or fictional speakers. Within this article, I provide a summary of the language creation process and how the community of conlangers, people who make languages, come to know each other's work, as well as how language creation assignments are being adopted within university classrooms. I also explore the role of the language creator in bringing a community of speakers into existence through the invention of a language. I discuss whether speakers of a constructed language are part of a community of practice or a speech community and the implications for this distinction within anthropology. I also describe conscripts, or constructed orthographies, as well as the relationship between endangered languages and constructed languages, how invented worlds can create real-world shifts in worldview, and suggestions for new directions in research linking anthropology and constructed languages. Expected final online publication date for the Annual Review of Anthropology, Volume 50 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Author(s):  
Marcelle de Carvalho Ribeiro ◽  
Gyongyi Szabo

The involvement of inflammasomes in the proinflammatory response observed in chronic liver diseases, such as alcohol-associated liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD), is widely recognized. Although there are different types of inflammasomes, most studies to date have given attention to NLRP3 (nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3) in the pathogenesis of ALD, NAFLD/nonalcoholic steatohepatitis, and fibrosis. Canonical inflammasomes are intracellular multiprotein complexes that are assembled after the sensing of danger signals and activate caspase-1, which matures interleukin (IL)-1β, IL-18, and IL-37 and also induces a form of cell death called pyroptosis. Noncanonical inflammasomes activate caspase-11 to induce pyroptosis. We discuss the different types of inflammasomes involved in liver diseases with a focus on ( a) signals and mechanisms of inflammasome activation, ( b) the role of different types of inflammasomes and their products in the pathogenesis of liver diseases, and ( c) potential therapeutic strategies targeting components of the inflammasomes or cytokines produced upon inflammasome activation. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Nikhil Mishra ◽  
Carl-Philipp Heisenberg

Multicellular organisms develop complex shapes from much simpler, single-celled zygotes through a process commonly called morphogenesis. Morphogenesis involves an interplay between several factors, ranging from the gene regulatory networks determining cell fate and differentiation to the mechanical processes underlying cell and tissue shape changes. Thus, the study of morphogenesis has historically been based on multidisciplinary approaches at the interface of biology with physics and mathematics. Recent technological advances have further improved our ability to study morphogenesis by bridging the gap between the genetic and biophysical factors through the development of new tools for visualizing, analyzing, and perturbing these factors and their biochemical intermediaries. Here, we review how a combination of genetic, microscopic, biophysical, and biochemical approaches has aided our attempts to understand morphogenesis and discuss potential approaches that may be beneficial to such an inquiry in the future. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Thomas Dresselhaus ◽  
Gerd Jürgens

Following fertilization in flowering plants (angiosperms), egg and sperm cells unite to form the zygote, which generates an entire new organism through a process called embryogenesis. In this review, we provide a comparative perspective on early zygotic embryogenesis in flowering plants by using the Poaceae maize and rice as monocot grass and crop models as well as Arabidopsis as a eudicot model of the Brassicaceae family. Beginning with the activation of the egg cell, we summarize and discuss the process of maternal-to-zygotic transition in plants, also taking recent work on parthenogenesis and haploid induction into consideration. Aspects like imprinting, which is mainly associated with endosperm development and somatic embryogenesis, are not considered. Controversial findings about the timing of zygotic genome activation as well as maternal versus paternal contribution to zygote and early embryo development are highlighted. The establishment of zygotic polarity, asymmetric division, and apical and basal cell lineages represents another chapter in which we also examine and compare the role of major signaling pathways, cell fate genes, and hormones in early embryogenesis. Except for the model Arabidopsis, little is known about embryo patterning and the establishment of the basic body plan in angiosperms. Using available in situ hybridization, RNA-sequencing, and marker data, we try to compare how and when stem cell niches are established. Finally, evolutionary aspects of plant embryo development are discussed. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Author(s):  
David Spielman ◽  
Els Lecoutere ◽  
Simrin Makhija ◽  
Bjorn Van Campenhout

With new possibilities offered by information and communications technology (ICT), an abundance of products, services, and projects has emerged with the promise of revitalizing agricultural extension in developing countries. However, a growing body of evidence suggests that not all ICT-enabled extension approaches are equally effective in improving adoption, productivity, income, or welfare outcomes. In this review, we explore various conceptual and methodological threads in the literature on ICT-enabled extension in developing countries. We examine the role of multiple impact pathways, highlighting how ICTs influence behaviors and preferences, gender and intrahousehold dynamics, spillovers, and public worker incentives. We also explore the opportunities presented by ICT-enabled extension for increasing the methodological rigor with which extension outcomes are identified. These conceptual and methodological insights—coupled with empirical evidence from prior studies—offer direction for several lines of policy-relevant research on ICT-enabled extension. Expected final online publication date for the Annual Review of Resource Economics, Volume 13 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2019 ◽  
Vol 20 (11) ◽  
pp. 2615 ◽  
Author(s):  
Pavan Kumar Puvvula

Long noncoding RNAs (lncRNAs) are a class of transcripts longer than 200 nucleotides with no open reading frame. They play a key role in the regulation of cellular processes such as genome integrity, chromatin organization, gene expression, translation regulation, and signal transduction. Recent studies indicated that lncRNAs are not only dysregulated in different types of diseases but also function as direct effectors or mediators for many pathological symptoms. This review focuses on the current findings of the lncRNAs and their dysregulated signaling pathways in senescence. Different functional mechanisms of lncRNAs and their downstream signaling pathways are integrated to provide a bird’s-eye view of lncRNA networks in senescence. This review not only highlights the role of lncRNAs in cell fate decision but also discusses how several feedback loops are interconnected to execute persistent senescence response. Finally, the significance of lncRNAs in senescence-associated diseases and their therapeutic and diagnostic potentials are highlighted.


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