[Campbell Biology P.1132] Based on the provided graph of an action potential, and assuming th... | Practice Question
Based on the provided graph of an action potential, and assuming the refractory period is equal to the total duration of a single action potential from threshold to the return to resting potential after the undershoot , what is the approximate maximum frequency action potentials per second, Hz at which this neuron could fire action potentials?
Explanation
The graph shows that the action potential, from the threshold -55 mV to the return to resting potential -70 mV after the undershoot, lasts approximately 4.5 milliseconds from time 1.5 ms to 6.0 ms on the x-axis . If the refractory period is equal to this duration, then the neuron can fire a new action potential roughly every 4.5 ms. To convert this to frequency Hz , we calculate 1 / 0.0045 seconds ≈ 222.2 Hz. Therefore, 200 Hz is the closest and most appropriate answer among the choices.