[Neuroscience] Equation that explains the behaviour of a circuit in voltage clamp

[Bill]

Hi,

I've already satisfied myself that the function to explain the
behaviour of a neuronal membrane (in current clamp) is
dV/dt = I/C  where I is the sum of all transmembrane currents

But what is the equation for a membrane under voltage clamp? That is
how does one explain the behaviour of the holding current I, in
response to membrane capacitance and changes in membrane conductances?

Thanks for any help.