Electrical Depolarization
Electrical Depolarization - Related Videos
08:31
FM Dye Cycling at the Synapse: Comparing High Potassium Depolarization, Electrical and Channelrhodopsin Stimulation
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Cited by 7 •
2018
Synaptic vesicle (SV) cycling is the core mechanism of intercellular communication at neuronal synapses. FM dye uptake and release are the primary means of quantitatively assaying SV endo- and exocytosis. Here, we compare all the stimulation methods to drive FM1-43 cycling at the Drosophila neuromuscular junction (NMJ) model synapse.
03:06
Investigating Prolonged Depolarizing Afterpotential (PDA) in Drosophila Photoreceptors
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2025
This video demonstrates an experimental protocol to investigate the prolonged depolarizing afterpotential (PDA) in white-eyed Drosophila. The fly's eye is exposed to intense blue light pulses to convert the photopigment rhodopsin to metarhodopsin, initiating a signaling cascade that opens positive ion channels and causes membrane depolarization. Because blue light prevents the reconversion of metarhodopsin to rhodopsin, the continuous influx of positive ions results in sustained depolarization,...
01:19
Depolarizing Blockers: Pharmocokinetics
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2023
Depolarizing blockers are administered through intravenous injection. Succinylcholine is the most common choice of depolarizing blockers in emergency clinical practices. Although they have a rapid onset, they readily diffuse away from the motor end plate into the extracellular fluid. They are metabolized by enzymes such as liver butyrylcholinesterase and plasma pseudocholinesterases. This produces a short duration of action, typically 5-10 minutes long, unlike nondepolarizing blockers, which...
14:16
A New Application of the Electrical Penetration Graph (EPG) for Acquiring and Measuring Electrical Signals in Phloem Sieve Elements
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Cited by 24 •
2015
Electrical Penetration Graph (EPG) is a well-established technique for studying the feeding behavior of stylet-bearing insects. Here we show a new application of EPG as a non-invasive tool for the acquisition of intracellular electrophysiology recordings of sieve elements (SEs), the cells that form the phloem vasculature in plants.
01:28
Depolarizing Blockers: Mechanism of Action
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2023
Depolarizing blockers act on skeletal muscle fibers' membranes and induce their depolarization. Most depolarizing blockers have two quaternary N+ atoms that bind the nicotinic acetylcholine receptors and cause neuromuscular blockade within minutes. Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
FAQs
The main contributors identified in this context are positively charged sodium and calcium ions entering the cell through opened ion channels. Their inward movement reduces the voltage difference between the cell interior and its surroundings. The relative contribution of either ion depends on the excitable cell and the channels opened by the stimulus.
Threshold marks the voltage level at which depolarization can trigger an action potential. A stimulus may shift the membrane voltage without producing this rapid electrical event if the threshold is not reached. Once threshold is achieved, the resulting action potential allows the cell to transmit an electrical signal along its membrane.
When depolarization reaches threshold and initiates an action potential, that electrical event propagates along the membrane. This propagation carries the signal beyond the region initially affected by the stimulus. In neurons, the process supports rapid nerve signaling, while in muscle fibers it helps connect electrical activity with contraction.
Studying this process helps connect changes in membrane voltage with several biological outcomes, including nerve signaling, muscle contraction, and sensory responses. It provides a framework for relating an initial stimulus to electrical activity in an excitable cell, then to communication or a functional response in nervous, muscular, or sensory systems.
Both neurons and muscle fibers are identified as excitable cells in which a stimulus can open ion channels and alter membrane voltage. In neurons, the resulting action potential supports nerve signaling. In muscle fibers, electrical activity is associated with contraction, showing how a shared membrane process can produce different cell-specific outcomes.
A sensory stimulus can produce ion-channel opening and a shift in membrane voltage, linking an external or cellular signal to electrical activity. If the voltage change reaches threshold, an action potential can follow and propagate along the membrane. This provides a cellular basis for studying how sensory information becomes a rapid biological signal.
Because drugs and disease can affect electrical activity in biological systems, examining depolarization helps researchers relate altered membrane-voltage behavior to changes in cellular signaling. The process can be considered across neurons, muscle fibers, and sensory cells, allowing investigators to study how disrupted or modified electrical responses may influence communication and function.