Direct measurement of fast axonal transport rates in corticospinal axons of the adult rat.
The bi-directional movement of proteins from the soma to the axon terminal is called axonal transport. Fast anterograde transport moves organelles and membrane-bound proteins distally. Fast transport rates were measured in corticospinal tract axons of male Sprague-Dawley rats by microinjection of tritiated proline into the sensorimotor cortex. Animals were killed after 3-5 h and the tract cut into 1 mm segments. A bimodal wave of radiolabeled proteins was evident, with the first peak at the spino-medullary junction and the second peak in cervical spinal segments. The fast transport rate was calculated at the leading edge of the distal wave, and found to be 303 +/- 44 mm/day.
Department of Anatomical Sciences, University of Oklahoma Health Sciences Center, College of Medicine, Oklahoma City 73190, USA.
J M
JM
Jacob
D L
DL
O'Donoghue
D000818:Animals; D001370:Axonal Transport / Q000502:physiology*; D001369:Axons / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D007700:Kinetics; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D017729:Presynaptic Terminals / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*
D009419:Nerve Tissue Proteins