Related Experiment Video
Updated: Jul 12, 2026
08:38
Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals
Published on: May 25, 2011
Time-dependent molecular memory in single voltage-gated sodium channel
1Molecular Biophysics Unit, Indian Institute of Science, Bangalore-12, India.
The Journal of Membrane Biology
|September 4, 2007
Summary
Sustained membrane depolarization alters voltage-gated sodium channels, introducing nonlinear properties and a "molecular memory" effect. This phenomenon, dependent on depolarization duration, impacts neuronal excitability.
Area of Science:
- Neuroscience
- Biophysics
- Ion Channel Physiology
Background:
- Neuronal excitability relies on action potentials, driven by voltage-gated sodium channels.
- Sustained membrane depolarization, common in conditions like epilepsy, can alter ion channel function.
Purpose of the Study:
- To investigate the impact of sustained membrane depolarization on single voltage-gated sodium (Na+) channels.
- To characterize the biophysical and kinetic changes induced by prolonged depolarization.
Main Methods:
- Single-channel activity of rNa(v)1.2 alpha channels was recorded using cell-attached patch-clamp.
- Classical statistical analysis, weighted wavelet Z transform, and discrete Fourier transform were employed.
- Hidden Markov models (HMM) were used for kinetic state analysis.
Main Results:
- Sustained depolarization induced complex nonlinear changes in channel dwell times and unitary conductance.
- Analysis revealed "pseudo-oscillatory" variations in kinetic parameters.
- HMM revealed significant alterations in kinetic states and transition rates.
- A "molecular memory" phenomenon, with clustered dwell times and autocorrelation, was observed and found to be duration-dependent.
Conclusions:
- Sustained membrane depolarization imparts novel nonlinear properties and a duration-dependent "molecular memory" to voltage-gated Na+ channels.
- These changes in channel dynamics may influence overall neuronal excitability.
- The findings offer insights into channel behavior under prolonged depolarizing conditions.
More Related Videos
10:29Multi-photon Intracellular Sodium Imaging Combined with UV-mediated Focal Uncaging of Glutamate in CA1 Pyramidal Neurons
Published on: October 8, 2014
11:12Registration of Calcium Transients in Mouse Neuromuscular Junction with High Temporal Resolution using Confocal Microscopy
Published on: December 1, 2021
Related Concept Videos
01:26Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
01:26Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
01:12Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
01:12Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
01:24Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.