www.neuron.yale.edu

I am just learning to use neuron to simulate real Drosophila neurons and encountered some confusion at the beginning.

Supposing I create a new cell body, add the passive attribute pas, add the current stim, specify e_pas and g_pas, and stim.amp, and use the default for others parameter. I can get the voltage change curve at a certain position of the cell body within the simulation time range.

The question I want to ask: how to understand the change in voltage? How to manually derive the voltage value at the specified location through the formula, and where to find the formula involved in the voltage change curve.

You could:
* take a course in computational neuroscience. Try to get one that focuses on modeling real neurons, not mathematicians' or physicists' neurons
* read a book. Most neuroscience textbooks are written by people who are experts in anatomy, or behavior, or molecular biology, or maybe genomics. Almost none of them contain anything about the equations that describe electrical and chemical signaling in real neurons. Fundamentals of Cellular Neurophysiology by Johnston and Wu is an excellent book. You might find chapters 4 and 5 of The NEURON Book by Carnevale and Hines to be helpful.