Dear Bijeet,

You need to specify if you want to correlate sodium conductance to presysnaptic release of ACh or to the ionic current flowing throught the cationic channel of nAChR.

In first case, the ACh release is spike-dependent, therefore the sodium conductance is the trigger of ACh release via the activation of voltage-activated calcium channels.

In the second case, nAChR being permeable to sodium and potassium ions, the driving force for sodium is the major parameter to calculate the ACh current.