Lithium stabilizes the mood of bipolar patients by depolarizing the neuronal membrane via quantum tunneling through the sodium channels.
Abdallah Barjas Qaswal *
School of Medicine, The university of Jordan
Received: June 29, 2019; Revised: August 13, 2019; Accepted: August 19, 2019; Published online: August 19, 2019.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Lithium is used as first line in treating bipolar patients to stabilize their mood. However, the exact mechanism of lithium is not yet established. One of the proposed mechanisms is that lithium depolarizes the hyperpolarized neuronal membrane of bipolar patients bringing it back to the normal potential. On the other hand, the only way that lithium causes significant therapeutic depolarization is to have a membrane conductance that must be at least an order of magnitude higher than that for sodium but this is not achieved since both; lithium and sodium have the same conductance because the membrane channels are selective for them approximately by the same degree. So, in this study, the idea of quantum tunneling of ions through the closed channels was used in a way to explain how lithium could have higher conductance than sodium and it was found that lithium can achieve higher conductance than sodium because it has a smaller mass than sodium making lithium to have higher probability of tunneling and consequently higher conductance through channels and membrane.
Keywords: Quantum tunneling, Sodium channel, Lithium, Bipolar disorder, Membrane potential