Axonal transport studied in a single vertebrate neuron: the giant electromotor neuron of the electric catfish, Malapterurus electricus.
Axonal transport was studied using a single vertebrate neuron, the giant electromotor neuron of the electric catfish, Malapterurus electricus. The electric organs of this strongly electric fish are innervated by two neurons whose axons form one electric nerve each. After injection of [35S]methionine into the spinal cord at the level of the two perikarya radioactively labelled material is exported by fast flow as a small wave with a velocity of 5.8 mm/h and a somal release time of 91 min (29 degrees C). Slow flow investigated between 15 and 39 days had a velocity of 1.36 mm/d at 29 degrees C. Analysis of radiolabelled proteins by polyacrylamide gel electrophoresis revealed different patterns of labelling between slow and fast flow. The relative molecular mass of the two major proteins labelled on slow flow correspond to actin and tubulin. Labelled proteins of higher relative molecular mass may correspond to neurofilament proteins. Our results suggest that this vertebrate single-neuron and single-axon system can be used successfully for axonal transport studies.
Zimmermann
H
H
Department of Biochemistry, Tokyo University Faculty of Medicine, Japan.
Tashiro
T
T
Komiya
Y
Y
Kurokawa
M
M
D000818:Animals; D001369:Axons / Q000378:metabolism*; D001692:Biological Transport; D004555:Electric Fish; D004557:Electric Organ / Q000166:cytology* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D013997:Time Factors