Pathophysiology of movement disorders due to gravity transitions: The channelopathy linkage in human balance and locomotion

Despite theoretical and experimental efforts to understand the space adaptation syndrome (SAS), which is responsible for spatial disorientation that severely affects physical and cognitive performance in astronauts, most of its pathophysiology is still unknown. As a consequence, countermeasures for SAS are not completely effective. Accordingly, in addition to the sensory-motor conflict theories, we propose that microgravity would affect the potassium channels of inner ear hair cells that would result in a temporal channelopathy as the most likely molecular origin for SAS, as well as being responsible for perpetuating movement disorders in gravity transition environments including those to be experienced by people visiting or living on the earth, moon, mars and beyond.