Exercise Two: The Action Potential

Get Started and make sure initial conditions are correct

Type runXoltolRun in the Matlab command window.
Select Exercise Two button.
Set initial conditions:
- Set current injection value to 0 pA.

Please complete Exercise Two:

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In this exercise, you will multiple simulations wherein you systematically increase the amount of current you inject into the recorded neuron. You will begin with injecting 0 pA and make some initial measurements.

Once you have measured the response following 0 pA current injection, you will re-run the simulation (runXolotlRun) with increasing levels of current.

Following each run, measure the relative change in the neuron's membrane potential in response to the current injection.

The relative change in voltage is measure as follows:

(a) Measure the membrane potential before the current injection pulse.

(b) Measure the maximum membrane potential (i.e., most depolarized potential) during the current injection.

Questions:

1. Measure & add your relative membrane potential changes for the following current injection values:

0 pA

6 pA

1 pA

7 pA

2 pA

8 pA

3 pA

9 pA

4 pA

5 pA

10 pA

2. At what current injection value did something interesting happen:

3. What do you call the event that occurred at the current injection value you listed in #2?

4. Why did the event occur? Explain your answer in terms of channel activity.

5. What happens to the relative change in membrane potential as you increase the current injection value beyond the value you listed in #2? For help, you may want to use Excel to plot current injection values VS relative change in membrane potential.

6. Explain the reason for your observation described in #5.

Thanks for submitting!