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What is the best way to create a fiber volley vs fEPSP slope curve?
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+ Neurochemistry
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ACE JEE-NEET CHEMISTRY
What is the best way to create a fiber volley vs fEPSP slope curve?
Diego, It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
Diego, It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
Dear Diego, The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc. You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP. The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips: 1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam). 2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure. 3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam. Hope that helps! cheers
Dear Diego, The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc. You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP. The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips: 1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam). 2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure. 3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam. Hope that helps! cheers
Thank you everybody very much for your help! Thanks Christophe for such useful tips for performing this curve. Unfortunately, during my recordings I am not able to see the fiber volley regularly. Sometimes it appears, but normally it is just "mixed" with the background noise. So I don't feel very confident to do this measurement. I found another possibility in a paper from Taqatqeh et al. (Taqatqeh J neurosci 2009 29). What they have done is to get a maximal saturated response with stimulus of 200 µs of duration, and after that, using the same stimulation intensity, they perform a curve for fEPSP slope responses against different durations for the stimulation ranging from 40 to 200 µs. What do you think about this procedure? Thank you!
Thank you everybody very much for your help! Thanks Christophe for such useful tips for performing this curve. Unfortunately, during my recordings I am not able to see the fiber volley regularly. Sometimes it appears, but normally it is just "mixed" with the background noise. So I don't feel very confident to do this measurement. I found another possibility in a paper from Taqatqeh et al. (Taqatqeh J neurosci 2009 29). What they have done is to get a maximal saturated response with stimulus of 200 µs of duration, and after that, using the same stimulation intensity, they perform a curve for fEPSP slope responses against different durations for the stimulation ranging from 40 to 200 µs. What do you think about this procedure? Thank you!
Diego, It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
Diego, It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
Hey Diego, People do both scenarios as you describe them. Your second option is indeed more work, but controls better for experimental variability. However, if you always position your electrodes in roughly same locations and your slice preparation does not show too much of a variability, the first option is perfectly acceptable. Minor differences between experimental groups may be harder to detect though. When you put FV amplitude on the x axis you don't always have to reproduce the exact amplitude once you bin your data and plot an error bar for x as well.
Hey Diego, People do both scenarios as you describe them. Your second option is indeed more work, but controls better for experimental variability. However, if you always position your electrodes in roughly same locations and your slice preparation does not show too much of a variability, the first option is perfectly acceptable. Minor differences between experimental groups may be harder to detect though. When you put FV amplitude on the x axis you don't always have to reproduce the exact amplitude once you bin your data and plot an error bar for x as well.
I agree with Christophe Bernard recommendations. I also would add that as always the necessity of keeping the electrical noise as low as possible is important. In brain slice work I found keeping a low bath level also helpful in reducing stimulus artifact size.
I agree with Christophe Bernard recommendations. I also would add that as always the necessity of keeping the electrical noise as low as possible is important. In brain slice work I found keeping a low bath level also helpful in reducing stimulus artifact size.
Dear Diego, The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc. You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP. The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips: 1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam). 2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure. 3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam. Hope that helps! cheers
Dear Diego, The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc. You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP. The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips: 1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam). 2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure. 3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam. Hope that helps! cheers
Diego,
It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
Diego,
It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
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Dear Diego,
The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP
Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc.
You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP.
The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips:
1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam).
2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure.
3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam.
Hope that helps!
cheers
Dear Diego,
The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP
Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc.
You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP.
The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips:
1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam).
2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure.
3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam.
Hope that helps!
cheers
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Thank you everybody very much for your help!
Thanks Christophe for such useful tips for performing this curve.
Unfortunately, during my recordings I am not able to see the fiber volley regularly. Sometimes it appears, but normally it is just "mixed" with the background noise. So I don't feel very confident to do this measurement.
I found another possibility in a paper from Taqatqeh et al. (Taqatqeh J neurosci 2009 29). What they have done is to get a maximal saturated response with stimulus of 200 µs of duration, and after that, using the same stimulation intensity, they perform a curve for fEPSP slope responses against different durations for the stimulation ranging from 40 to 200 µs. What do you think about this procedure?
Thank you!
Thank you everybody very much for your help!
Thanks Christophe for such useful tips for performing this curve.
Unfortunately, during my recordings I am not able to see the fiber volley regularly. Sometimes it appears, but normally it is just "mixed" with the background noise. So I don't feel very confident to do this measurement.
I found another possibility in a paper from Taqatqeh et al. (Taqatqeh J neurosci 2009 29). What they have done is to get a maximal saturated response with stimulus of 200 µs of duration, and after that, using the same stimulation intensity, they perform a curve for fEPSP slope responses against different durations for the stimulation ranging from 40 to 200 µs. What do you think about this procedure?
Thank you!
More
VOTE
Diego,
It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
Diego,
It is easiest to plot the fiber volley amplitude against the fEPSP slope for each individual slice placement, rather than trying to match fiber volleys. This will mean that you will have different values for each slice (placement). Then you can plot a sigmoidal function (FV vs. fEPSP) and use a predicted value from that curve for each slice to add to group data. For example, FV1/2, which would be the fiber volley that evokes a 1/2 maximal fEPSP response. This is a value that will normalize across slices within groups and can then be averaged and compared across groups.
More
VOTE
Hey Diego,
People do both scenarios as you describe them. Your second option is indeed more work, but controls better for experimental variability. However, if you always position your electrodes in roughly same locations and your slice preparation does not show too much of a variability, the first option is perfectly acceptable. Minor differences between experimental groups may be harder to detect though.
When you put FV amplitude on the x axis you don't always have to reproduce the exact amplitude once you bin your data and plot an error bar for x as well.
Hey Diego,
People do both scenarios as you describe them. Your second option is indeed more work, but controls better for experimental variability. However, if you always position your electrodes in roughly same locations and your slice preparation does not show too much of a variability, the first option is perfectly acceptable. Minor differences between experimental groups may be harder to detect though.
When you put FV amplitude on the x axis you don't always have to reproduce the exact amplitude once you bin your data and plot an error bar for x as well.
More
VOTE
You can see an example of the different I/O that you could generate in this paper
Article Kalirin-7 is necessary for normal NMDA receptor-dependent sy...
You can see an example of the different I/O that you could generate in this paper
Article Kalirin-7 is necessary for normal NMDA receptor-dependent sy...
More
VOTE
I agree with Christophe Bernard recommendations. I also would add that as always the necessity of keeping the electrical noise as low as possible is important. In brain slice work I found keeping a low bath level also helpful in reducing stimulus artifact size.
I agree with Christophe Bernard recommendations. I also would add that as always the necessity of keeping the electrical noise as low as possible is important. In brain slice work I found keeping a low bath level also helpful in reducing stimulus artifact size.
More
VOTE
Dear Diego,
The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP
Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc.
You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP.
The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips:
1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam).
2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure.
3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam.
Hope that helps!
cheers
Dear Diego,
The proper way to do it is to increase progressively the stimulus intensity, and to plot the fiber volley amplitude versus slope of fEPSP
Since you never get the same fiber volley across slices/animals/conditions you just bin the fiber volley say from 0 to 0.5; 0.51 to 1.0; 1.01 to 1.51 (artificial units); etc.
You calculate the average and SEM in each bin for the volley amplitude and slope of fEPSP. This makes a point with double error bars (one horizontal for fiber volley amplitude and vertical for slope of fEPSP.
The difficult part is to get a nice fiber volley, not contaminated by the stimulation artefact. These are key experimental tips:
1. always ensure that your recording electrode and the stimulus electrodes are aligned along the path of the axons (on beam).
2. use twisted wire (i.e. 50 microns NiCr twisted wire) for stimulation, or better glass theta tube with both barrels filled with ACSF (gives the smallest artefact) - my preferred procedure.
3. you have to carefully adjust the distance between the stim and the recording electrode with trial and errors. The closer you are, the more contamination you get from the artefact. The further you are, the more difficult it is to be on beam.
Hope that helps!
cheers
More
VOTE