So is it sodium or Potassium??

Scientists at Salk Institute for Biological Studies have recently found an connection between two ion channels which may be the reason for many symptoms that classically characterize Multiple Sclerosis. As we have gone over in discussion, Multiple Sclerosis is a chronic demyelinating disease in which the immune system attacks the insulating myelin sheaths of axons in the CNS. This consequently is the cause of the many neurological symptoms that accompany MS such as; numbness, tingling, muscle weakness, paralysis and vision loss. Myelin sheaths speed up the signals that axons transmit. However, once damaged, axons are no longer able to generate an impulse (causing loss of sensation and weakness) or may become hyper excitable and then overcompensate by firing even in the absence of input which causes twitching. In either scenario, the improper transduction of signals is the root of many symptoms MS patients suffer from on a daily basis. In this particular study Terrence J. Sejnowski, the head of the Salk Institutes Computation Neurobiology Laboratory and leader of the study, created a computer model of axonal transmission with myelinated and demyelinated sections. They then used a program that modeled every part of the axon by breaking it into segments. They did this in order to keep track of the ions (particularly sodium and potassium) going in and out of each section. In many previous studies, scientists had focused on the sodium channel in particular. This being because the sodium channel is responsible for initiating the action potential. Hence, many MS drugs also focus on sodium channels. However, in this study scientists were surprised to see that it wasn't merely the amount of sodium, but the ratio of densities between the sodium and potassium channel that sets the ground state current of the neuron, which then determines whether the neuron can fire properly. They found this when their study demonstrated that drops in sodium levels that were followed by a drop in the leak current levels (potassium levels) maintained the signal of the neuron. They then found that if the sodium levels dropped and the leak current (potassium) didn't, signal transmission may fail. Therefore they were able to conclude that, "Trying to influence the balance between the two ion channels is a completely new approach, and drugs that target leak current could be as important as those targeting sodium current" - Sejnowski. Sejnowski and his group plan on further investigating the sodium/leak current as it can have application to other medical issues along with Multiple Sclerosis and other demyelinating diseases. With this study they could possibly open up a whole new perspective on signal transduction in MS which could hopefully bring about creation of new medicines to help MS patients alleviate the chronic symptoms that accompany this so far incurable disease.