Axonal Varicosities
Axonal Varicosities - Related Videos
03:04
Inducing Axonal Varicosities with a Micromechanical Stimulus on Neurons
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2025
This video demonstrates the induction of axonal varicosities by applying micromechanical stimulus on neurons. The system comprises a micropipette attached to a syringe containing buffer via tubing. Using a micromanipulator, the micropipette is positioned above the neurons. Fluid pressure is then applied to induce varicosities in axons.
09:58
A Microbiomechanical System for Studying Varicosity Formation and Recovery in Central Neuron Axons
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Cited by 4 •
2018
This protocol describes a physiologically relevant, pressurized fluid approach for rapid and reversible induction of varicosities in neurons.
01:26
Varicose Veins I: Introduction
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2025
Varicose veins, or varicosities, are abnormally dilated and twisted superficial veins caused by venous valve incompetence. This condition commonly affects the lower extremities, especially the saphenous veins, due to the higher pressure from prolonged standing and walking. However, varicosities can also occur in other areas, such as the esophagus, vulva, spermatic cords, and anorectal region.Etiology and typesPrimary varicose veins, often idiopathic, are more common in women due to inherent...
03:24
Two-Photon Laser Axotomy: A Method to Injure Axons in Zebrafish Embryos and Observe Axonal Recovery
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2023
This video describes the method to injure axons in zebrafish embryos using two photon laser axotomy and observing axonal recovery from injury.
01:26
Varicose Veins II: Diagnostic Studies and Interprofessional Care
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2025
Varicose veins, or varicosities, develop when the valves in the veins, which control blood flow, weaken or damage. It causes blood to pool and the veins to enlarge. Understanding the clinical manifestations, diagnostic approaches, and management options for varicose veins is crucial for effective treatment and relief.Clinical manifestationsClinical manifestations of varicose veins include a heavy, achy feeling or pain after prolonged standing or sitting. This discomfort can often be relieved by...
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An arriving action potential depolarizes the varicosity membrane and opens voltage-gated calcium channels. The resulting calcium influx acts as the immediate trigger for synaptic vesicles to fuse with the axonal membrane and release neurotransmitter. This coupling links electrical activity to chemical signaling, allowing the varicosity to convert propagation along the axon into communication with nearby neurons or other target cells.
En passant boutons can release neurotransmitter from swellings located along the axon without forming a clearly defined postsynaptic contact at the release site. Conventional synapses are generally described through a more distinct presynaptic and postsynaptic arrangement. Because the release site may lack a sharply aligned partner, signaling from an en passant bouton can influence targets through the surrounding extracellular space.
Release into the extracellular space allows neurotransmitter effects to extend beyond a single, tightly apposed postsynaptic membrane. This diffuse movement supports volume transmission, in which chemical signals can influence nearby cells without a clearly defined synaptic junction. The mechanism is important for understanding how local axonal activity can shape broader patterns of communication within neural circuits.
Their release arrangement allows neurotransmitters to act through spatially diffuse chemical signaling rather than only through point-to-point synaptic contacts. That feature makes axonal varicosities relevant to neuromodulation, where chemical signals influence the activity or responsiveness of neural elements across a surrounding region. Studying them therefore helps connect local transmitter release with broader regulation of circuit behavior.
A useful analysis follows the sequence from action-potential arrival to membrane depolarization, opening of voltage-gated calcium channels, calcium influx, vesicle fusion, and transmitter diffusion. Examining these linked stages distinguishes electrical propagation from chemical release and then from extracellular spread. It also provides a framework for interpreting how a localized axonal event produces effects in nearby target cells.
Investigation of these structures can reveal how neurons communicate when release sites do not have clearly defined postsynaptic partners. In particular, the findings help researchers examine neuromodulation, volume transmission, and the influence of diffuse chemical signals on neural circuits. This perspective expands circuit analysis beyond narrowly aligned synapses to include signaling across the extracellular space.