My textbook seems to gloss over this subject. Once the post-synaptic receptors are activated, do they cause particular ion channels to open, letting positive charge into the cell and inching the neuron closer to the AP threshold?
Also, does the action potential start in the dendrites or the axon? Does the cell body experience membrane voltage? If so, how does the charge get past all the miscellaneous organelles in the cell body? Does it have like a special charge pipe to go down? Or do the ions just float past the organelles?