first off, I've watched like 7 youtube videos, read a bunch of articles, and the explanations for why myelination actually increases action potential propagation differ each time are very vague. I've read and heard that because action potentials only occur on the nodes of Ranvier, that it simply takes less time for them to travel down an axon. I get that, but I was under the impression that increased +ve charge = further generation of action potentials. if that is the case, wouldn't that mean that myelination should slow it down as there is less +ve charge influx? I understand that it takes time for action potentials to be generated, but is the variable affecting the rate at which they occur not the influx of +ve charge, and wouldn't this positive charge be less if there are fewer action potentials generated? it's not like myelination decreases the time taken for particular na+ channels to open, right? ftr, I'm not doubting that myelination speeds up action potential propagation, I just don't get it and the explanations are contradictory (nothing that I've mentioned here is contradictory to my knowledge FYI, I just mean that I have heard other contradictory explanations). I understand that it insulates the neuron, thus preventing k+ leakage. Does the insulation possibly increase the rate of propagation by decreasing the ability of extracellular ions from interacting with intracellular neurons? I would understand that I suppose since then there wouldn't be positively charged particles on the exterior exerting electric force upon the intracellular +vely charged particles, thus making it easier for +ve charge to spread throughout the negatively charged axon. even if there is any truth in that, could that possibly compensate for the decrease in intracellular sodium that the decreased amount of na+ influx channels would imply?
thanks to anyone who responds! a long one for sure, lol.