In the previous experiment we varied the stimulus strength while keeping stimulus duration constant, and we saw that a stronger stimulus increases the firing rate of a neuron. But does this firing rate stay constant during however long we decide to keep the stimulus on?
As it turns out, neurons have a mechanism called spike rate adaptation (or spike frequency adaptation), which slows down the firing rate once it's been generating action potentials for a period of time.
In this simulation we will have a constant stimulus strength of 35 nA and we will vary the stimulus duration, to see how the firing rate differs between the start and end of a short stimulus duration, versus a longer one.
Varying spike rate
Stimulus strength: 35 nA
Fill out this table with the values from the simulation. Hovering over a point in the graph will give you the x and y values, round your answer to the nearest tenth of a millisecond (i.e. one decimal digit).
|Time interval between peaks of:
|First two action potentials
|Last two action potentials