scholarly journals Unraveling Axon Guidance during Axotomy and Regeneration

2021 ◽  
Vol 22 (15) ◽  
pp. 8344
Author(s):  
Miguel E. Domínguez-Romero ◽  
Paula G. Slater
Keyword(s):  
Nervous System ◽  
Growth Cone ◽  
Neuronal Development ◽  
System Development ◽  
Nervous System Development ◽  
Signaling Cascades ◽  
Final Destination ◽  
Guidance Cues ◽  
The Central Nervous System ◽  
Do So

During neuronal development and regeneration axons extend a cytoskeletal-rich structure known as the growth cone, which detects and integrates signals to reach its final destination. The guidance cues “signals” bind their receptors, activating signaling cascades that result in the regulation of the growth cone cytoskeleton, defining growth cone advance, pausing, turning, or collapse. Even though much is known about guidance cues and their isolated mechanisms during nervous system development, there is still a gap in the understanding of the crosstalk between them, and about what happens after nervous system injuries. After neuronal injuries in mammals, only axons in the peripheral nervous system are able to regenerate, while the ones from the central nervous system fail to do so. Therefore, untangling the guidance cues mechanisms, as well as their behavior and characterization after axotomy and regeneration, are of special interest for understanding and treating neuronal injuries. In this review, we present findings on growth cone guidance and canonical guidance cues mechanisms, followed by a description and comparison of growth cone pathfinding mechanisms after axotomy, in regenerative and non-regenerative animal models.

scholarly journals Incorporation of 5-Bromo-2′-deoxyuridine into DNA and Proliferative Behavior of Cerebellar Neuroblasts: All That Glitters Is Not Gold

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1453
Author(s):  
Joaquín Martí-Clúa
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Nervous System Development ◽  
Current Data ◽  
Cellular Mechanisms ◽  
Dividing Cells ◽  
The Central Nervous System ◽  
Repeated Doses ◽  
Pyrimidine Analog

The synthetic halogenated pyrimidine analog, 5-bromo-2′-deoxyuridine (BrdU), is a marker of DNA synthesis. This exogenous nucleoside has generated important insights into the cellular mechanisms of the central nervous system development in a variety of animals including insects, birds, and mammals. Despite this, the detrimental effects of the incorporation of BrdU into DNA on proliferation and viability of different types of cells has been frequently neglected. This review will summarize and present the effects of a pulse of BrdU, at doses ranging from 25 to 300 µg/g, or repeated injections. The latter, following the method of the progressively delayed labeling comprehensive procedure. The prenatal and perinatal development of the cerebellum are studied. These current data have implications for the interpretation of the results obtained by this marker as an index of the generation, migration, and settled pattern of neurons in the developing central nervous system. Caution should be exercised when interpreting the results obtained using BrdU. This is particularly important when high or repeated doses of this agent are injected. I hope that this review sheds light on the effects of this toxic maker. It may be used as a reference for toxicologists and neurobiologists given the broad use of 5-bromo-2′-deoxyuridine to label dividing cells.

Pain and immunity

2021 ◽  
pp. 67-71
Author(s):  
Simon Beggs
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Early Life ◽  
System Development ◽  
Later Life ◽  
Nervous System Development ◽  
Neuronal Function ◽  
Neuronal Homeostasis ◽  
Neuroimmune Interactions ◽  
The Central Nervous System

The central nervous system (CNS) and immune system are inextricably linked. The complexity of their interactions is still being unraveled, but the list of processes mediated wholly or in part by neuroimmune interactions continues to grow. The influence of the immune system is crucial for normal nervous system development both pre- and postnatally, for maintaining neuronal homeostasis in the mature CNS and modulating synaptic plasticity. Aberrations in this crosstalk have been implicated in many neurodevelopmental and psychiatric disorders. It is not feasible to explore neuronal function at any point in the lifespan, in health or disease, without considering the influence of the immune system. In the adult animal it is now well established that pain chronicity is maintained by immune influence upon the neuronal nociceptive system, although, fascinatingly, there is now evidence for a marked sexual dimorphism in how the immune and nervous systems interact. This holds true for pain in early life, where the two still-developing systems provide a very different environment to mediate nociception and pain. Of particular interest is how the immune system and sex interact to early life painful events to prime pain responses in later life.

scholarly journals sli is required for proper morphology and migration of sensory neurons in the Drosophila PNS

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Madison Gonsior ◽  
Afshan Ismat
Keyword(s):  
Nervous System ◽  
Sensory Neurons ◽  
Glial Cells ◽  
System Development ◽  
Nervous System Development ◽  
Final Position ◽  
Neuron Development ◽  
Guidance Cues ◽  
And Migration

Abstract Neurons and glial cells coordinate with each other in many different aspects of nervous system development. Both types of cells are receiving multiple guidance cues to guide the neurons and glial cells to their proper final position. The lateral chordotonal organs (lch5) of the Drosophila peripheral nervous system (PNS) are composed of five sensory neurons surrounded by four different glial cells, scolopale cells, cap cells, attachment cells and ligament cells. During embryogenesis, the lch5 neurons go through a rotation and ventral migration to reach their final position in the lateral region of the abdomen. We show here that the extracellular ligand sli is required for the proper ventral migration and morphology of the lch5 neurons. We further show that mutations in the Sli receptors Robo and Robo2 also display similar defects as loss of sli, suggesting a role for Slit-Robo signaling in lch5 migration and positioning. Additionally, we demonstrate that the scolopale, cap and attachment cells follow the mis-migrated lch5 neurons in sli mutants, while the ventral stretching of the ligament cells seems to be independent of the lch5 neurons. This study sheds light on the role of Slit-Robo signaling in sensory neuron development.

scholarly journals Cbln1 regulates axon growth and guidance in multiple neural regions

2021 ◽  
Author(s):  
Sheng-Jian Ji ◽  
Peng Han ◽  
Yuanchu She ◽  
Zhuoxuan Yang ◽  
Mengru Zhuang ◽  
...  
Keyword(s):  
Nervous System ◽  
Axon Guidance ◽  
Neural Development ◽  
System Development ◽  
Axon Growth ◽  
Nervous System Development ◽  
Precise Control ◽  
Commissural Neurons ◽  
Guidance Cues ◽  
Guidance Cue

The accurate construction of neural circuits requires the precise control of axon growth and guidance, which is regulated by multiple growth and guidance cues during early nervous system development. It is generally thought that the growth and guidance cues that control the major steps of axon guidance have been defined. Here, we describe cerebellin-1 (Cbln1) as a novel cue that controls diverse aspects of axon growth and guidance throughout the central nervous system (CNS). Cbln1 has previously been shown to function in late neural development to influence synapse organization. Here we find that Cbln1 has an essential role in early neural development. Cbln1 is expressed on the axons and growth cones of developing commissural neurons and functions in an autocrine manner to promote axon growth. Cbln1 is also expressed in intermediate target tissues and functions as an attractive guidance cue. We find that these functions of Cbln1 are mediated by neurexin-2 (Nrxn2), which functions as the Cbln1 receptor for axon growth and guidance. In addition to the developing spinal cord, we further show that Cbln1 functions in diverse parts of the CNS with major roles in cerebellar parallel fiber growth and retinal ganglion cell axon guidance. Despite the prevailing role of Cbln1 as a synaptic organizer, our study discovers a new and unexpected function for Cbln1 as a general axon growth and guidance cue throughout the nervous system.

scholarly journals Neuromesodermal Lineage Contribution to CNS Development in Invertebrate and Vertebrate Chordates

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 592
Author(s):  
Clare Hudson ◽  
Hitoyoshi Yasuo
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Neural Tissue ◽  
Nervous System Development ◽  
Cns Development ◽  
Neural Fate ◽  
The Central Nervous System ◽  
Ascidian Embryos ◽  
Anterior Posterior

Ascidians are invertebrate chordates and the closest living relative to vertebrates. In ascidian embryos a large part of the central nervous system arises from cells associated with mesoderm rather than ectoderm lineages. This seems at odds with the traditional view of vertebrate nervous system development which was thought to be induced from ectoderm cells, initially with anterior character and later transformed by posteriorizing signals, to generate the entire anterior-posterior axis of the central nervous system. Recent advances in vertebrate developmental biology, however, show that much of the posterior central nervous system, or spinal cord, in fact arises from cells that share a common origin with mesoderm. This indicates a conserved role for bi-potential neuromesoderm precursors in chordate CNS formation. However, the boundary between neural tissue arising from these distinct neural lineages does not appear to be fixed, which leads to the notion that anterior-posterior patterning and neural fate formation can evolve independently.

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