Related Experiment Video
Updated: Jun 23, 2026
11:07
In Vivo Intracellular Recording of Type-Identified Rat Spinal Motoneurons During Trans-Spinal Direct Current Stimulation
Published on: May 11, 2020
Modulation of axonal excitability by high-frequency biphasic electrical current.
Hailong Liu1, James R Roppolo, William C de Groat
1Department of Urology and Department of Pharmacology, University of Pittsburgh, Pittsburgh, PA 15261 USA.
IEEE Transactions on Bio-Medical Engineering
|April 25, 2009
Summary
High-frequency biphasic electrical current can alter axonal excitability by modulating ion channel activity. This finding may enable selective nerve fiber activation, advancing understanding of nerve conduction block.
Area of Science:
- Neuroscience
- Computational Biology
- Biophysics
Background:
- Axonal excitability is crucial for nerve signal transmission.
- Understanding how electrical stimulation affects nerve fibers is key to therapeutic applications.
Purpose of the Study:
- To analyze the modulation of axonal excitability by high-frequency biphasic (HFB) electrical current.
- To investigate the underlying mechanisms of HFB current's effects on nerve fibers.
Main Methods:
- A lumped-circuit model of the myelinated axon was employed.
- The model was based on the Schwarz-Reid-Bostock (SRB) equations.
Main Results:
- HFB current can increase or decrease axonal excitability based on intensity.
- Increased excitability is linked to sodium channel activation; decreased excitability involves potassium channel activation.
- The location of excitability modulation shifts with increasing HFB current intensity.
Conclusions:
- HFB electrical current offers potential for selective activation of small nerve fibers.
- Further research will clarify mechanisms of HFB-induced nerve conduction block.
Related Concept Videos
01:14Action Potential
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
01:14Action Potential
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
01:41Action Potentials
Overview
01:19The Role of Ion Channels in Neuronal Computation
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
01:23Propagation of Action Potentials
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
01:28Action Potential: Phases of Stimulation
The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...