Related Experiment Video
Updated: May 17, 2026
12:51
Voltage-sensitive Dye Recording from Axons, Dendrites and Dendritic Spines of Individual Neurons in Brain Slices
Published on: November 29, 2012
Multiple spike time patterns occur at bifurcation points of membrane potential dynamics
J Vincent Toups1, Jean-Marc Fellous, Peter J Thomas
1Computational Neurophysics Laboratory, Department of Physics & Astronomy, University of North Carolina, Chapel Hill, NC, USA.
Plos Computational Biology
|October 25, 2012
Summary
Neuronal responses to fluctuating currents show reliable action potentials. Bifurcation points reveal multiple spike patterns, increasing information about the stimulus.
Area of Science:
- Neuroscience
- Computational Neuroscience
Background:
- Neurons generate action potentials in response to stimuli.
- Precise timing of action potentials is crucial for neural communication.
Purpose of the Study:
- To investigate the reproducibility of neuronal spike timing under varying current injection conditions.
- To understand how stimulus amplitude and background activity affect neuronal response patterns.
Main Methods:
- In vitro somatic current injections into cortical neurons.
- Systematic variation of current waveform amplitude and DC offset.
- Unsupervised classification to identify distinct spike timing patterns.
Main Results:
- Increased current amplitude enhanced spike reliability and stability.
- Bifurcation points were identified where small stimulus changes caused large spike timing shifts.
- Increased DC offset also revealed bifurcation points and shifted spike times earlier.
- Multiple spike patterns emerged at bifurcation points, containing distinct stimulus information.
Conclusions:
- Neuronal spike timing exhibits complex dynamics, including bifurcations, under fluctuating input.
- Background network activity (DC offset) influences spike timing and reliability.
- Despite reduced reliability at bifurcation points, information transfer about the stimulus can be enhanced.
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...
01:28Action 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...
01:28Integration of Synaptic Events
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to...
01:41Action Potentials
Overview
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...