<p>I think there are many ways to accomplish this in terms of technical detail, but they will all boil down to measuring the arrival of an action potential along the axon on at least two points with known distance from each other on the axon. From these two arrival times the latency can be deducted. Then, by dividing the distance between the elektrodes by the latency (i.e., the time it took the action potential from going from electrode 1 to number 2), the conduction speed can be estimated. In a paper by <a href="https://bio-protocol.org/e2152#:%7E:text=Conduction%20velocity%20can%20be%20measured,through%20which%20the%20axon%20projects.&amp;text=The%20ionic%20currents%20that%20flow,neuron%2C%20using%20extracellular%20recording%20electrodes." rel="nofollow noreferrer">DeMaegd <em>et al</em>. (2017)</a> they use extracellular electrodes and the figure in their paper is quite informative (Fig.1 ).</p>
<p><a href="https://i.sstatic.net/7NLC5.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/7NLC5.png" alt="conduction_velocity" /></a><br />
<sup>Fig. 1. Measuring axon conduction velocity by recording action potentials. source: <a href="https://bio-protocol.org/e2152#:%7E:text=Conduction%20velocity%20can%20be%20measured,through%20which%20the%20axon%20projects.&amp;text=The%20ionic%20currents%20that%20flow,neuron%2C%20using%20extracellular%20recording%20electrodes." rel="nofollow noreferrer">DeMaegd <em>et al</em>. (2017)</a></sup></p>
<p><sub><strong>Reference</strong><br />
<strong>-</strong> <a href="https://bio-protocol.org/e2152#:%7E:text=Conduction%20velocity%20can%20be%20measured,through%20which%20the%20axon%20projects.&amp;text=The%20ionic%20currents%20that%20flow,neuron%2C%20using%20extracellular%20recording%20electrodes." rel="nofollow noreferrer">DeMaegd <em>et al</em>., <em>Bio Protocol</em> (2017); <strong>7</strong>(5)</a></sub></p>

CC BY-SA 4.0
2021-02-12T03:47:03.007Z
Thanks but in C where signal is generated between wells , for well 1 wouldn't that mean signal is going backwards which is highly is restricted  and why is second signal more sharp i.e more amplitude than before should it not attentuate (or is that because of amplification - related to experimental setup ?)
pavan sai
CC BY-SA 4.0
2021-02-12T08:11:05.503Z
@pavansai - The retrograde AP in (C) is certainly possible; axons are not unidirectional; on the contrary, they sustain 2-way traffic. The refractory characteristics take care of the restriction  that a running action potential proceeds unidirectionally and cannot propagate back to its point of origin. This restriction applies to anterograde APs as well as for antidromic APs. The different shape of the 2 APs in the graph have no physiological meaning; they are drawn that way in panels B and C identically.
AliceD
CC BY-SA 4.0
2021-02-13T05:18:50.213Z
thanks for explaining
pavan sai
CC BY-SA 4.0
2021-02-11T12:15:26.650Z
2021-02-12T07:09:06.097Z
2021-02-12T07:09:06.097Z
AliceD
<p>Can anyone suggest good sources or papers to understand about experimental setup and procedure for measuring nerve conduction velocity for various types of neurons?</p>
<p>I wish to learn how such experiments are done and get insight on how they were able to classify neurons based on conduction velocities as (alpha beta gamma) or I / II / III grade neurons especially for neurons that have small distances between axon and dendrites for it might be difficult to insert probes at cell body and measure signal at the synapse of that neuron to measure time elapsed in signal conduction or they measure for few neurons in chain and average out the time taken for conduction velocity.</p>

<neuroscience><methodology><neurophysiology><electrophysiology><experimental-neuroscience>
How to determine nerve conduction velocity?
pavan sai
# How to determine nerve conduction velocity?

(Asked by: username_0 on 2021-02-10)

Can anyone suggest good sources or papers to understand about experimental setup and procedure for measuring nerve conduction velocity for various types of neurons?

I wish to learn how such experiments are done and get insight on how they were able to classify neurons based on conduction velocities as (alpha beta gamma) or I / II / III grade neurons especially for neurons that have small distances between axon and dendrites for it might be difficult to insert probes at cell body and measure signal at the synapse of that neuron to measure time elapsed in signal conduction or they measure for few neurons in chain and average out the time taken for conduction velocity.

**Tags:** neuroscience, methodology, neurophysiology, electrophysiology, experimental-neuroscience


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## 1 answers

### Answer by username_1 on 2021-02-11. Score: 2

I think there are many ways to accomplish this in terms of technical detail, but they will all boil down to measuring the arrival of an action potential along the axon on at least two points with known distance from each other on the axon. From these two arrival times the latency can be deducted. Then, by dividing the distance between the elektrodes by the latency (i.e., the time it took the action potential from going from electrode 1 to number 2), the conduction speed can be estimated. In a paper by [DeMaegd *et al*. (2017)](https://bio-protocol.org/e2152#:%7E:text=Conduction%20velocity%20can%20be%20measured,through%20which%20the%20axon%20projects.&text=The%20ionic%20currents%20that%20flow,neuron%2C%20using%20extracellular%20recording%20electrodes.) they use extracellular electrodes and the figure in their paper is quite informative (Fig.1 ).

[![conduction_velocity](https://i.sstatic.net/7NLC5.png)](https://i.sstatic.net/7NLC5.png)  
Fig. 1. Measuring axon conduction velocity by recording action potentials. source: [DeMaegd *et al*. (2017)](https://bio-protocol.org/e2152#:%7E:text=Conduction%20velocity%20can%20be%20measured,through%20which%20the%20axon%20projects.&text=The%20ionic%20currents%20that%20flow,neuron%2C%20using%20extracellular%20recording%20electrodes.)

**Reference**  
**-** [DeMaegd *et al*., *Bio Protocol* (2017); **7**(5)](https://bio-protocol.org/e2152#:%7E:text=Conduction%20velocity%20can%20be%20measured,through%20which%20the%20axon%20projects.&text=The%20ionic%20currents%20that%20flow,neuron%2C%20using%20extracellular%20recording%20electrodes.)

> **Comments:**
> **username_0**: Thanks but in C where signal is generated between wells , for well 1 wouldn't that mean signal is going backwards which is highly is restricted  and why is second signal more sharp i.e more amplitude than before should it not attentuate (or is that because of amplification - related to experimental setup ?)  
> **username_1**: @pavansai - The retrograde AP in (C) is certainly possible; axons are not unidirectional; on the contrary, they sustain 2-way traffic. The refractory characteristics take care of the restriction  that a running action potential proceeds unidirectionally and cannot propagate back to its point of origin. This restriction applies to anterograde APs as well as for antidromic APs. The different shape of the 2 APs in the graph have no physiological meaning; they are drawn that way in panels B and C identically.  
> **username_0**: thanks for explaining  

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