External detection of axoplasmic transport using 32P-ATP as precursor

The design and construction of a multiple proportional counter used to study axonal transport

The design and construction of a multiple proportional counter, a position-sensitive detector of ionizing radiation, are described. Both the mechanical and electronic aspects are discussed. Testing procedures are outlined, and test values are cited.

Axoplasmic transport of microtubule-associated proteins in the rat sciatic nerve

32P-ATP was injected into the L5 dorsal root ganglion and axoplasmic transport of the phosphorylate MA proteins 2, microtubule-associated proteins 2, was observed. After the injection of 32P-ATP, the nerve was dissected out at prescribed time intervals and sliced into 5-mm pieces. Each segment was electrophoresed on an SDS-polyacrylamide slab gel and subjected to autoradiography. A protein of 310,000 dalton was transported at a velocity of 6.6-10.6 mm/day in the axon with the electrophoretic mobility identical to that of MA proteins 2, one of the key components associated with the microtubules.