For which of the following reasons was the development of the voltage clamp critical to investigations of the ionic basis of the action potential?

For which of the following reasons was the development of the voltage clamp critical to investigations of the ionic basis of the action potential?

For which of the following reasons was the development of the voltage clamp critical to investigations of the ionic basis of the action potential?





  1. Voltage changes in the cell cannot be seen without voltage clamp.
  2. Ionic conductances can be activated only in cells that have been voltage clamped.
  3. Voltage clamping allows simultaneous control of membrane potential and measurement of permeability changes.
  4. Sodium and potassium currents are activated in non-overlapping voltage regimes.
  5. All of the above

Answer: 3