scholarly journals Axonal chemokine-like Orion induces astrocyte infiltration and engulfment during mushroom body neuronal remodeling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ana Boulanger ◽  
Camille Thinat ◽  
Stephan Züchner ◽  
Lee G. Fradkin ◽  
Hugues Lortat-Jacob ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Nervous System ◽  
Mushroom Body ◽  
Active Role ◽  
Mushroom Bodies ◽  
Axon Pruning ◽  
Neuronal Remodeling ◽  
Neuronal Signal ◽  
And Function ◽  
Fundamental Mechanism

AbstractThe remodeling of neurons is a conserved fundamental mechanism underlying nervous system maturation and function. Astrocytes can clear neuronal debris and they have an active role in neuronal remodeling. Developmental axon pruning ofDrosophilamemory center neurons occurs via a degenerative process mediated by infiltrating astrocytes. However, how astrocytes are recruited to the axons during brain development is unclear. Using an unbiased screen, we identify the gene requirement oforion, encoding for a chemokine-like protein, in the developing mushroom bodies. Functional analysis shows that Orion is necessary for both axonal pruning and removal of axonal debris. Orion performs its functions extracellularly and bears some features common to chemokines, a family of chemoattractant cytokines. We propose that Orion is a neuronal signal that elicits astrocyte infiltration and astrocyte-driven axonal engulfment required during neuronal remodeling in theDrosophiladeveloping brain.

scholarly journals Axon-secreted chemokine-like Orion is a signal for astrocyte infiltration during neuronal remodeling

2020 ◽  
Author(s):  
Ana Boulanger ◽  
Camille Thinat ◽  
Stephan Züchner ◽  
Lee G. Fradkin ◽  
Hugues Lortat-Jacob ◽  
...  
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Active Role ◽  
Cell Interaction ◽  
Axon Pruning ◽  
Neuronal Remodeling ◽  
New Gene ◽  
Neuronal Signal ◽  
And Function ◽  
Fundamental Mechanism

SummaryThe remodeling of neurons is a conserved fundamental mechanism underlying nervous system maturation and function. Glial cells are known to clear neuronal debris but also to have an active role in the remodeling process. Developmental axon pruning of Drosophila memory center neurons occurs by a degenerative process mediated by infiltrating astrocytes. However, how these glial processes are recruited by the axons is unknown. In an unbiased screen, we identified a new gene (orion) which is necessary for both the pruning of some axons and removal of the resulting debris. Orion is secreted from the neurons and bears some features common to the chemokines, a family of chemoattractant cytokines. Thus, chemokine involvement in neuron/glial cell interaction is an evolutionarily ancient mechanism. We propose that Orion is the neuronal signal that elicits astrocyte infiltration required for developmental neuronal remodeling.

scholarly journals Silencing neuronal activity is required for developmental circuit remodeling

2021 ◽  
Author(s):  
Oded Mayseless ◽  
El-Yazid Rachad ◽  
Gal Shapira ◽  
Andre Fiala ◽  
Oren Schuldiner
Keyword(s):  
Nervous System ◽  
Neuronal Activity ◽  
Mushroom Body ◽  
Excitatory Synapses ◽  
Neuronal Connectivity ◽  
Axon Pruning ◽  
Kenyon Cells ◽  
Inward Rectifying Potassium Channel ◽  
Developmental Remodeling

Postnatal refinement of neuronal connectivity shapes the mature nervous system. Pruning of exuberant connections involves both cell autonomous and non-cell autonomous mechanisms, such as neuronal activity. While the role of neuronal activity in the plasticity of excitatory synapses has been extensively studied, the involvement of inhibition is less clear. Furthermore, the role of activity during stereotypic developmental remodeling, where competition is not as apparent, is not well understood. Here we use the Drosophila mushroom body as a model to show that regulated silencing of neuronal activity is required for developmental axon pruning of the γ-Kenyon cells. We demonstrate that silencing neuronal activity is mechanistically achieved by cell autonomous expression of the inward rectifying potassium channel (irk1) combined with inhibition by the GABAergic APL neuron. These results support the Hebbian-like rule 'use it or lose it', where inhibition can destabilize connectivity and promote pruning while excitability stabilizes existing connections.

scholarly journals Tripartite Mushroom Body Architecture Revealed by Antigenic Markers

1998 ◽  
Vol 5 (1) ◽  
pp. 38-51 ◽  
Author(s):  
Jill R. Crittenden ◽  
Efthimios M.C. Skoulakis ◽  
Kyung-An Han ◽  
Daniel Kalderon ◽  
Ronald L. Davis
Keyword(s):  
Mushroom Body ◽  
Dorsal Surface ◽  
Mushroom Bodies ◽  
Lateral Projection ◽  
Body Cell ◽  
Expression Levels ◽  
Form And Function ◽  
Immunohistochemical Markers ◽  
And Function

We have explored the organization of the axonal lobes in Drosophila mushroom bodies by using a panel of immunohistochemical markers. These markers consist of antibodies to eight proteins expressed preferentially in the mushroom bodies: DAMB, DCO, DRK, FASII, LEO, OAMB, PKA RII, and RUT. Previous to this work, four axonal lobes, two projecting dorsally (α and α′) and two medially (β and γ), had been described inDrosophila mushroom bodies. However, our analysis of immunohistochemically stained frontal and sagittal sections of the brain revealed three medially projecting lobes. The newly distinguished lobe, which we term β′, lies along the dorsal surface of β, just posterior to γ. In addition to resolving a fifth lobe, our studies revealed that there are specific lobe sets defined by equivalent marker expression levels. These sets are (1) the α and β lobes, (2) the α′ and β′ lobes, and (3) the γ lobe and heel (a lateral projection formed by a hairpin turn of some of the peduncle fibers). All of the markers we have examined are consistent with these three sets. Previous Golgi studies demonstrate that each mushroom body cell projects one axon that branches into a dorsal lobe and a medial lobe, or one unbranched axon that projects medially. Taken together with the lobe sets listed above, we propose that there are three major projection configurations of mushroom body cell axons: (1) one branch in the α and one in the β lobe, (2) one branch in the α′ and one in the β′ lobe, and (3) one unbranched axon projecting to the heel and the γ lobe. The fact that these neuron types exhibit differential expression levels of a number of mushroom body genes suggests that they may have corresponding functional differences. These functions may be conserved in the larvae, as several of these genes were expressed in larval and embryonic mushroom bodies as well. The basic mushroom body structure, including the denritic calyx, peduncle, and lobes, was already visible by the late stages of embryogenesis. With new insights into mushroom body organization, and the characterization of markers for developing mushroom bodies, we are beginning to understand how these structures form and function.

Plant hormones, plant growth regulators

2014 ◽  
Vol 155 (26) ◽  
pp. 1011-1018 ◽  
Author(s):  
György Végvári ◽  
Edina Vidéki
Keyword(s):  
Nervous System ◽  
Growth And Development ◽  
Large Scale ◽  
Essential Role ◽  
Higher Plants ◽  
Structure And Function ◽  
Wide Sense ◽  
Large Scale Integration ◽  
Scale Integration ◽  
And Function

Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy beween organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants’ life. Orv. Hetil., 2014, 155(26), 1011–1018.

Natural Products for the Treatment of Neurodegenerative Diseases

2020 ◽  
Vol 27 (34) ◽  
pp. 5790-5828 ◽  
Author(s):  
Ze Wang ◽  
Chunyang He ◽  
Jing-Shan Shi
Keyword(s):  
Nervous System ◽  
Natural Products ◽  
Neurodegenerative Diseases ◽  
Neuroprotective Effect ◽  
Rapid Development ◽  
New Drugs ◽  
Progressive Degeneration ◽  
Cord Injury ◽  
The Central Nervous System ◽  
And Function

Neurodegenerative diseases are a heterogeneous group of disorders characterized by the progressive degeneration of the structure and function of the central nervous system or peripheral nervous system. Alzheimer's Disease (AD), Parkinson's Disease (PD) and Spinal Cord Injury (SCI) are the common neurodegenerative diseases, which typically occur in people over the age of 60. With the rapid development of an aged society, over 60 million people worldwide are suffering from these uncurable diseases. Therefore, the search for new drugs and therapeutic methods has become an increasingly important research topic. Natural products especially those from the Traditional Chinese Medicines (TCMs), are the most important sources of drugs, and have received extensive interest among pharmacist. In this review, in order to facilitate further chemical modification of those useful natural products by pharmacists, we will bring together recent studies in single natural compound from TCMs with neuroprotective effect.

scholarly journals Implication of Contactins in Demyelinating Pathologies

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Ilias Kalafatakis ◽  
Maria Savvaki ◽  
Theodora Velona ◽  
Domna Karagogeos
Keyword(s):  
Nervous System ◽  
White Matter ◽  
Cell Adhesion Molecules ◽  
White Matter Lesions ◽  
Myelinated Axon ◽  
Immunoglobulin Superfamily ◽  
Proper Function ◽  
Myelinated Axons ◽  
And Function

Demyelinating pathologies comprise of a variety of conditions where either central or peripheral myelin is attacked, resulting in white matter lesions and neurodegeneration. Myelinated axons are organized into molecularly distinct domains, and this segregation is crucial for their proper function. These defined domains are differentially affected at the different stages of demyelination as well as at the lesion and perilesion sites. Among the main players in myelinated axon organization are proteins of the contactin (CNTN) group of the immunoglobulin superfamily (IgSF) of cell adhesion molecules, namely Contactin-1 and Contactin-2 (CNTN1, CNTN2). The two contactins perform their functions through intermolecular interactions, which are crucial for myelinated axon integrity and functionality. In this review, we focus on the implication of these two molecules as well as their interactors in demyelinating pathologies in humans. At first, we describe the organization and function of myelinated axons in the central (CNS) and the peripheral (PNS) nervous system, further analyzing the role of CNTN1 and CNTN2 as well as their interactors in myelination. In the last section, studies showing the correlation of the two contactins with demyelinating pathologies are reviewed, highlighting the importance of these recognition molecules in shaping the function of the nervous system in multiple ways.

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