scholarly journals Unc-4 acts to promote neuronal identity and development of the take-off circuit in the Drosophila CNS

2019 ◽  
Author(s):  
Haluk Lacin ◽  
W. Ryan Williamson ◽  
Gwyneth M. Card ◽  
James B. Skeath ◽  
James W. Truman
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Transcription Factor ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Functional Organization ◽  
Neuronal Circuits ◽  
Sense Organs ◽  
Neuronal Identity ◽  
Cholinergic Neurotransmitter

ABSTRACTThe Drosophila ventral nerve cord (VNC), the fly equivalent of the spinal cord, is composed of thousands of neurons that are born from a set of individually identifiable stem cells. The VNC harbors neuronal circuits required for the execution of vital behaviors, such as flying and walking. Taking advantage of the lineage-based functional organization of the VNC and genetic tools we developed, we investigated the molecular and developmental basis of behavior by focusing on lineage-specific functions of the homeodomain transcription factor, Unc-4. We found that Unc-4 functions in lineage 11A to promote cholinergic neurotransmitter identity and suppress the GABA fate. In 7B lineage, Unc-4 promotes proper neuronal projections to the leg neuropil, the hub for leg-related neuronal circuits and a specific flight-related take-off behavior. We also uncovered that Unc-4 acts peripherally to promote the development of proprioceptive sense organs and the abilities of flies to execute specific leg-related behaviors such as walking, climbing, and grooming. Our findings, thus, initiates the work on revealing molecular and developmental events that shape the VNC related behaviors.

scholarly journals Unc-4 acts to promote neuronal identity and development of the take-off circuit in the Drosophila CNS

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Haluk Lacin ◽  
W Ryan Williamson ◽  
Gwyneth M Card ◽  
James B Skeath ◽  
James W Truman
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Nerve Cord ◽  
Molecular Basis ◽  
Ventral Nerve Cord ◽  
Functional Organization ◽  
Time Dependent ◽  
Knock Out ◽  
Neuronal Identity ◽  
Cholinergic Neurotransmitter

The Drosophila ventral nerve cord (VNC) is composed of thousands of neurons born from a set of individually identifiable stem cells. The VNC harbors neuronal circuits required to execute key behaviors, such as flying and walking. Leveraging the lineage-based functional organization of the VNC, we investigated the developmental and molecular basis of behavior by focusing on lineage-specific functions of the homeodomain transcription factor, Unc-4. We found that Unc-4 functions in lineage 11A to promote cholinergic neurotransmitter identity and suppress the GABA fate. In lineage 7B, Unc-4 promotes proper neuronal projections to the leg neuropil and a specific flight-related take-off behavior. We also uncovered that Unc-4 acts peripherally to promote proprioceptive sensory organ development and the execution of specific leg-related behaviors. Through time-dependent conditional knock-out of Unc-4, we found that its function is required during development, but not in the adult, to regulate the above events.

scholarly journals Neurotransmitter identity is acquired in a lineage-restricted manner in the Drosophila CNS

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Haluk Lacin ◽  
Hui-Min Chen ◽  
Xi Long ◽  
Robert H Singer ◽  
Tzumin Lee ◽  
...  
Keyword(s):  
Stem Cell ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Gabaergic Neurons ◽  
Simple Rule ◽  
Specific Gene ◽  
Neuronal Circuits ◽  
Cell Level ◽  
Fast Acting

The vast majority of the adult fly ventral nerve cord is composed of 34 hemilineages, which are clusters of lineally related neurons. Neurons in these hemilineages use one of the three fast-acting neurotransmitters (acetylcholine, GABA, or glutamate) for communication. We generated a comprehensive neurotransmitter usage map for the entire ventral nerve cord. We did not find any cases of neurons using more than one neurotransmitter, but found that the acetylcholine specific gene ChAT is transcribed in many glutamatergic and GABAergic neurons, but these transcripts typically do not leave the nucleus and are not translated. Importantly, our work uncovered a simple rule: All neurons within a hemilineage use the same neurotransmitter. Thus, neurotransmitter identity is acquired at the stem cell level. Our detailed transmitter- usage/lineage identity map will be a great resource for studying the developmental basis of behavior and deciphering how neuronal circuits function to regulate behavior.

scholarly journals A terminal selector prevents a Hox transcriptional switch to safeguard motor neuron identity throughout life

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Weidong Feng ◽  
Yinan Li ◽  
Pauline Dao ◽  
Jihad Aburas ◽  
Priota Islam ◽  
...  
Keyword(s):  
Ion Channels ◽  
Motor Neurons ◽  
General Principle ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Neurotransmitter Receptors ◽  
Dual Function ◽  
C Elegans ◽  
Neuronal Identity ◽  
Transcriptional Switch

To become and remain functional, individual neuron types must select during development and maintain throughout life their distinct terminal identity features, such as expression of specific neurotransmitter receptors, ion channels and neuropeptides. Here, we report a molecular mechanism that enables cholinergic motor neurons (MNs) in the C. elegans ventral nerve cord to select and maintain their unique terminal identity. This mechanism relies on the dual function of the conserved terminal selector UNC-3 (Collier/Ebf). UNC-3 synergizes with LIN-39 (Scr/Dfd/Hox4-5) to directly co-activate multiple terminal identity traits specific to cholinergic MNs, but also antagonizes LIN-39’s ability to activate terminal features of alternative neuronal identities. Loss of unc-3 causes a switch in the transcriptional targets of LIN-39, thereby alternative, not cholinergic MN-specific, terminal features become activated and locomotion defects occur. The strategy of a terminal selector preventing a transcriptional switch may constitute a general principle for safeguarding neuronal identity throughout life.

Extracellular filaments in the perineurium of the florida lobster, Panulirus argus

1987 ◽  
Vol 45 ◽  
pp. 784-785
Author(s):  
Roy J. Baerwald ◽  
Lura C. Williamson
Keyword(s):  
Blood Brain Barrier ◽  
Glial Cells ◽  
Tannic Acid ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Brain Barrier ◽  
Cacodylate Buffer ◽  
Nerve Cords

In arthropods the perineurium surrounds the neuropile, consists of modified glial cells, and is the morphological basis for the blood-brain barrier. The perineurium is surrounded by an acellular neural lamella, sometimes containing scattered collagen-like fibrils. This perineurial-neural lamellar complex is thought to occur ubiquitously throughout the arthropods. This report describes a SEM and TEM study of the sheath surrounding the ventral nerve cord of Panulirus argus.Juvenile P. argus were collected from the Florida Keys and maintained in marine aquaria. Nerve cords were fixed for TEM in Karnovsky's fixative and saturated tannic acid in 0.1 M Na-cacodylate buffer, pH = 7.4; post-fixed in 1.0% OsO4 in the same buffer; dehydrated through a graded series of ethanols; embedded in Epon-Araldite; and examined in a Philips 200 TEM. Nerve cords were fixed for SEM in a similar manner except that tannic acid was not used.

Stem Cell Transplantation: A Promising Therapy for Spinal Cord Injury

2020 ◽  
Vol 15 (4) ◽  
pp. 321-331 ◽  
Author(s):  
Zhe Gong ◽  
Kaishun Xia ◽  
Ankai Xu ◽  
Chao Yu ◽  
Chenggui Wang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Therapeutic Potential ◽  
Embryonic Stem ◽  
Current Status ◽  
Cord Injury

Spinal Cord Injury (SCI) causes irreversible functional loss of the affected population. The incidence of SCI keeps increasing, resulting in huge burden on the society. The pathogenesis of SCI involves neuron death and exotic reaction, which could impede neuron regeneration. In clinic, the limited regenerative capacity of endogenous cells after SCI is a major problem. Recent studies have demonstrated that a variety of stem cells such as induced Pluripotent Stem Cells (iPSCs), Embryonic Stem Cells (ESCs), Mesenchymal Stem Cells (MSCs) and Neural Progenitor Cells (NPCs) /Neural Stem Cells (NSCs) have therapeutic potential for SCI. However, the efficacy and safety of these stem cellbased therapy for SCI remain controversial. In this review, we introduce the pathogenesis of SCI, summarize the current status of the application of these stem cells in SCI repair, and discuss possible mechanisms responsible for functional recovery of SCI after stem cell transplantation. Finally, we highlight several areas for further exploitation of stem cells as a promising regenerative therapy of SCI.

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