Practically speaking, how would you determine that Na + influx into a cell underlies the early current? Group of answer choices Remove Na + from the extracellular compartment and assess the early current under new conditions. Use the voltage clamp method to measure the current. Remove K + from the intracellular compartment and assess the early current under the new conditions. Treat the cell with tetraethylammonium. Replace intracellular Na + with its radioactive form and trace its movement across the membrane.

Remove Na + from the extracellular compartment and assess the early current under new conditions

Explanation:

Na+ is a critical ion that influences the action potential in nerve cells. During the transmission of an impulse, the cell membrane is open so ions can flow through it, i.e., positively charged ions such as sodium ions (Na +) move within the cell, while negatively charged ions move outside the cell. This process produces a change in the action potential by rapidly increasing the positive charge in the nerve fiber, being thus the impulse propagated when this charge reaches +40 mv. In consequence, the effects of Na + on the single-channel current can be analyzed by removing positive ions and determining the change in the reversal potential of this channel.