Question

Activity 3: • At what voltage did you first notice an action potential (AP)? What is this voltage typically called? • What happened to the peak voltage value when you increased the stimulus voltage?

Answer 1

1. The voltage at which you first notice the action potential is -55 mV. This value of this voltage is called threshold potential.

The resting membrane potential is almost -70 mV. When you apply a voltage to the cell an action potential is fired only when voltage reaches to the threshold potential i.e. -55 mV.

2. There will be no change in the peak value of action potential with increase in stimulus voltage.

The peak value of an action potential occurs at +30 mV which is always constant for all action potentials. Only the frequency of action potential changes.