The figures show the timecourse of an action potential and the associated conductances of Na⁺ and K+ for a very large axon. The following information describes the conditions for this recording:

temperature = 18 degrees C

resting potential = -68 mV

axon surface area = 1 cm²

[K⁺]_out = 25 mM

[K⁺]_in = 440 mM

E_K⁺ = -72 mV

[Na⁺]_out = 220 mM

[Na⁺]in = not reported

E_Na⁺ = 43 mV

Calculate the Na⁺ current that is flowing at the time indicated by the arrow (i.e., at 1 ms). Express your answer to the nearest uA. (You must include units. Use the letter u to represent the greek character mu. Do not leave any spaces in your answer. E.g., 75uA)

4. 3 2 1 0 +4 2 2468 321 2 Iepualod auelquiaN GUID / sulau-acul) aouelonpuoD 4. 3 2 1 0 +4 2 2468 321 2 Iepualod auelquiaN GUID / sulau-acul) aouelonpuoD