Dendritic trafficking for neuronal growth and plasticity

2013 ◽  
Vol 41 (6) ◽  
pp. 1365-1382 ◽  
Author(s):  
Michael D. Ehlers

Among the largest cells in the body, neurons possess an immense surface area and intricate geometry that poses many unique cell biological challenges. This morphological complexity is critical for neural circuit formation and enables neurons to compartmentalize cell–cell communication and local intracellular signalling to a degree that surpasses other cell types. The adaptive plastic properties of neurons, synapses and circuits have been classically studied by measurement of electrophysiological properties, ionic conductances and excitability. Over the last 15 years, the field of synaptic and neural electrophysiology has collided with neuronal cell biology to produce a more integrated understanding of how these remarkable highly differentiated cells utilize common eukaryotic cellular machinery to decode, integrate and propagate signals in the nervous system. The present article gives a very brief and personal overview of the organelles and trafficking machinery of neuronal dendrites and their role in dendritic and synaptic plasticity.

2021 ◽  
Vol 22 (7) ◽  
pp. 3649
Author(s):  
Patricia Ramos-Ramírez ◽  
Omar Tliba

Glucocorticoids (GCs) act via the GC receptor (GR), a receptor ubiquitously expressed in the body where it drives a broad spectrum of responses within distinct cell types and tissues, which vary in strength and specificity. The variability of GR-mediated cell responses is further extended by the existence of GR isoforms, such as GRα and GRβ, generated through alternative splicing mechanisms. While GRα is the classic receptor responsible for GC actions, GRβ has been implicated in the impairment of GRα-mediated activities. Interestingly, in contrast to the popular belief that GRβ actions are restricted to its dominant-negative effects on GRα-mediated responses, GRβ has been shown to have intrinsic activities and “directly” regulates a plethora of genes related to inflammatory process, cell communication, migration, and malignancy, each in a GRα-independent manner. Furthermore, GRβ has been associated with increased cell migration, growth, and reduced sensitivity to GC-induced apoptosis. We will summarize the current knowledge of GRβ-mediated responses, with a focus on the GRα-independent/intrinsic effects of GRβ and the associated non-canonical signaling pathways. Where appropriate, potential links to airway inflammatory diseases will be highlighted.


2018 ◽  
Vol 62 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Adam J. Poe ◽  
Anne A. Knowlton

Exosomes have become an important player in intercellular signaling. These lipid microvesicles can stably transfer miRNA, protein, and other molecules between cells and circulate throughout the body. Exosomes are released by almost all cell types and are present in most if not all biological fluids. The biologically active cargo carried by exosomes can alter the phenotype of recipient cells. Exosomes increasingly are recognized as having an important role in the progression and treatment of cardiac disease states. Injured cardiac cells can release exosomes with important pathological effects on surrounding tissue, in addition to effecting other organs. But of equal interest is the possible benefit(s) conferred by exosomes released from stem cells for use in treatment and possible repair of cardiac damage.


2016 ◽  
Vol 27 (2) ◽  
pp. 78
Author(s):  
Simon Gelman

Optogenetics is a novel technology with the widely acknowledged potential to revolutionize cell biology and neuroscience. Essentially, optogenetic methods integrate optical and genetic tools to control the activity of whole cells or subcellular events. In recent years, optogenetics has been used to activate and to inhibit genetically defined neuronal populations within neural circuits. As such, it has been used to show the sufficiency or the necessity of specific neuronal cell types in generating behaviors across a number of animal species. When employed in rodent models of human neurological and psychiatric disorders, optogenetics has provided clinically relevant insights into the function of pathologic neural circuits. Recent progress in the in vivo applications of this methodology is reviewed in this article, with particular focus on behavioral applications in nematodes, fish, rodents, and nonhuman primates.


2019 ◽  
Author(s):  
Elizabeth Normand ◽  
Catherine Browning ◽  
Mark Zervas

SUMMARYGene expression is a dynamic process, which is highly coordinated during development to ensure the proper allocation and identity of neuronal cell types within the brain. Equally important during neurodevelopment is how cohorts of neurons establish axonal projections that innervate terminal target sites. We sought to bridge the temporal dynamics of gene expression, within a specific genetic lineage, to the establishment of neuronal circuits derived from cohorts of the lineage-specific progenitors. A central goal was to be able to accomplish genetic inducible circuit mapping non-invasively and with commonly available CreER/loxP technology. Specifically, we genetically marked thalamic neuron progenitors that expressed the transcription factor Gbx2 at an early embryonic stage and tracked the formation of lineage-derived thalamocortical axons during embryogenesis. We then assessed the neural circuitry at an early postnatal stage. We show that the temporal specificity of lineage marking provides a high degree of clarity for following neural circuit development. We also determined that the onset and duration of gene expression can delineate subsets of neural circuits derived from a common lineage. For example, we uncovered a novel contribution of Gbx2-expressing progenitors to midbrain dopamine neurons and dopaminergic axons of the medial forebrain bundle. We anticipate that this system can be instructive in elucidating changes in neural circuit development in both normal development and in mutant mice in which neural circuit formation is altered.


2017 ◽  
Vol 97 (4) ◽  
pp. 1235-1294 ◽  
Author(s):  
Chris Siebel ◽  
Urban Lendahl

Notch signaling is an evolutionarily highly conserved signaling mechanism, but in contrast to signaling pathways such as Wnt, Sonic Hedgehog, and BMP/TGF-β, Notch signaling occurs via cell-cell communication, where transmembrane ligands on one cell activate transmembrane receptors on a juxtaposed cell. Originally discovered through mutations in Drosophila more than 100 yr ago, and with the first Notch gene cloned more than 30 yr ago, we are still gaining new insights into the broad effects of Notch signaling in organisms across the metazoan spectrum and its requirement for normal development of most organs in the body. In this review, we provide an overview of the Notch signaling mechanism at the molecular level and discuss how the pathway, which is architecturally quite simple, is able to engage in the control of cell fates in a broad variety of cell types. We discuss the current understanding of how Notch signaling can become derailed, either by direct mutations or by aberrant regulation, and the expanding spectrum of diseases and cancers that is a consequence of Notch dysregulation. Finally, we explore the emerging field of Notch in the control of tissue homeostasis, with examples from skin, liver, lung, intestine, and the vasculature.


2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Mayra Silva Miranda ◽  
Adrien Breiman ◽  
Sophie Allain ◽  
Florence Deknuydt ◽  
Frederic Altare

One of the main features of the immune response toM. Tuberculosisis the formation of an organized structure called granuloma. It consists mainly in the recruitment at the infectious stage of macrophages, highly differentiated cells such as multinucleated giant cells, epithelioid cells and Foamy cells, all these cells being surrounded by a rim of lymphocytes. Although in the first instance the granuloma acts to constrain the infection, some bacilli can actually survive inside these structures for a long time in a dormant state. For some reasons, which are still unclear, the bacilli will reactivate in 10% of the latently infected individuals, escape the granuloma and spread throughout the body, thus giving rise to clinical disease, and are finally disseminated throughout the environment. In this review we examine the process leading to the formation of the granulomatous structures and the different cell types that have been shown to be part of this inflammatory reaction. We also discuss the differentin vivoandin vitromodels available to study this fascinating immune structure.


2020 ◽  
Author(s):  
Csaba Verasztó ◽  
Sanja Jasek ◽  
Martin Gühmann ◽  
Réza Shahidi ◽  
Nobuo Ueda ◽  
...  

AbstractNervous systems coordinate effectors across the body during movements. We know little about the cellular-level structure of synaptic circuits for such body-wide control. Here we describe the whole-body synaptic connectome and cell-type complement of a three-segmented larva of the marine annelid Platynereis dumerilii. We reconstructed and annotated over 1,500 neurons and 6,500 non-neuronal cells in a whole-body serial electron microscopy dataset. The differentiated cells fall into 180 neuronal and 90 non-neuronal cell types. We analyse the modular network architecture of the entire nervous system and describe polysynaptic pathways from 428 sensory neurons to four effector systems – ciliated cells, glands, pigment cells and muscles. The complete somatic musculature and its innervation will be described in a companion paper. We also investigated intersegmental differences in cell-type complement, descending and ascending pathways, and mechanosensory and peptidergic circuits. Our work provides the basis for understanding whole-body coordination in annelids.


2021 ◽  
pp. 1-18
Author(s):  
Jonathan Slack

‘What are stem cells?’ explains that a stem cell is a cell that can both reproduce itself and generate offspring of different functional cell types and begins by considering the nature of cells in general, wherein cells are understood to be the ultimate structural unit of an animal or plant body. Stem cells in the body persist long term, usually for the lifetime of the organism. Good examples of differentiated cells arising from stem cells are those of the skin, the blood, and the lining of the intestine. Embryonic stem cells are grown in culture from early mammalian embryos. The reason that stem cell research is seen as the source for new cures is largely because this technology offers a route to cell therapy.


Author(s):  
Hisham F. Bahmada ◽  
Mohamad K. Elajami ◽  
Reem Daouk ◽  
Hiba Jalloul ◽  
Batoul Darwish ◽  
...  

: Stem cells are undifferentiated cells with the ability to proliferate and convert to different types of differentiated cells that make up the various tissues and organs in the body. They exist both in embryos as pluripotent stem cells that can differentiate into the three germ layers and as multipotent or unipotent stem cells in adult tissues to aid in repair and homeostasis. Perturbations in these cells’ normal functions can give rise to a wide variety of diseases. In this review, we discuss the origin of different stem cell types, their properties and characteristics, their role in tissue homeostasis, current research, and their potential applications in various life-threatening diseases. We focus on neural stem cells, their role in neurogenesis and how they can be exploited to treat diseases of the brain including neurodegenerative diseases and cancer. Next, we explore current research in induced pluripotent stem cell (iPSC) techniques and their clinical applications in regenerative and personalized medicine. Lastly, we tackle a special type of stem cells called cancer stem cells (CSCs) and how they can be responsible for therapy resistance and tumor recurrence and explore ways to target them.


2004 ◽  
Vol 287 (1) ◽  
pp. C171-C181 ◽  
Author(s):  
Yaron Daniely ◽  
Grace Liao ◽  
Darlene Dixon ◽  
R. Ilona Linnoila ◽  
Adriana Lori ◽  
...  

The trachea and esophagus originate from the foregut endoderm during early embryonic development. Their epithelia undergo a series of changes involving the differentiation of stem cells into unique cell types and ultimately forming the mature epithelia. In this study, we monitored the expression of p63 in the esophagus and the trachea during development and examined in detail morphogenesis in p63−/− mice. At embryonic day 15.5 (E15.5), the esophageal and tracheobronchial epithelia contain two to three layers of cells; however, only the progenitor cells express p63. These progenitor cells differentiate first into ciliated cells (p63−/β-tubulin IV+) and after birth into mature basal cells (p63+/K14+/K5+/BS-I-B4+). In the adult pseudostratified, columnar tracheal epithelium, K14+/K5+/BS-I-B4+ basal cells stain most intensely for p63, whereas ciliated and mucosecretory cells are negative. In stratified squamous esophageal epithelium and during squamous metaplasia in the trachea, cells in the basal layer stain strongest for p63, whereas p63 staining declines progressively in transient amplifying and squamous differentiated cells. Generally, p63 expression is restricted to human squamous cell carcinomas, and adenocarcinomas and Barrett's metaplasia do not stain for p63. Examination of morphogenesis in newborn p63−/− mice showed an abnormal persistence of ciliated cells in the esophagus. Significantly, in both tissues, lack of p63 expression results in the development of a highly ordered, columnar ciliated epithelium deficient in basal cells. These observations indicate that p63 plays a critical role in the development of normal esophageal and tracheobronchial epithelia and appears to control the commitment of early stem cells into basal cell progeny and the maintenance of basal cells.


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