How does our breathing affect our nervous system? 🧠 When we hyperventilate, we decrease the amount of free calcium in the blood. This causes sodium channels on neurons to become unstable, and sodium begins to come into the cell, raising the resting membrane threshold and making the cell more easily excitable. So why does this matter clinically? When neurons sit closer to threshold, they require less stimuli in order to depolarize. This can cause firing of nerves in otherwise insignificant stimulations. It is important to note that the effects of hyperventilation are different for sensory and motor fibers.