The axon initial segment and the maintenance of neuronal polarity.
Ion channel clustering at the axon initial segment (AIS) and nodes of Ranvier has been suggested to be a key evolutionary innovation that enabled the development of the complex vertebrate nervous system. This innovation epitomizes a signature feature of neurons, namely polarity. The mechanisms that establish neuronal polarity, channel clustering and axon-dendrite identity during development are becoming clearer. However, much less is known about how polarity is maintained throughout life. Here, I review the role of the AIS in the development and maintenance of neuronal polarity and discuss how disrupted polarity may be a common component of many diseases and injuries that affect the nervous system.
Rasband
Matthew N
MN
Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA. Rasband@bcm.edu
D000818:Animals; D001369:Axons / Q000737:chemistry / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D006801:Humans; D009422:Nervous System Diseases / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000502:physiology*