"It is well-known that calcium is another positive molecule useful for the conduction of a nerve impulse to a muscle fiber. However, Clay Armstrong, a neurobiologist, believes that calcium may play a larger role. Armstrong suspects that calcium is in charge of the gated channels that release potassium and sodium to facilitate a nerve impulse. Armstrong's theory proposes that calcium ions are like a door to these gated channels. Calcium must move to release the ions and calcium must return before the impulse will stop and homeostasis is returned "