Electro-physiologists can measure the electrical potential (=voltage) across a cell membrane using micro-electrodes. Recalling that this potential is due to an uneven distribution of charged ions across a membrane, consider the following case: When you expose the cells of the electric organ of the electric eel to the signaling molecule acetylcholine, the electrical potential across these cells membranes rapidly becomes more positive. Give a plausible explanation for this observation, focusing on the type of signal receptor that might be involved.