Journal of Neuroscience, Vol 1, 1113-1116, Copyright © 1981 by Society for Neuroscience
Notexin preferentially inhibits the release of newly synthesized acetylcholine from rat brain synaptosomal fractions
CB Gundersen and DJ Jenden
An investigation was made of the effects of the snake venom neurotoxin,
notexin, on acetylcholine turnover in rat brain P2 fractions using a gas
chromatographic mass spectrometric assay for acetylcholine and choline. In
contrast to earlier reports, we found a stimulation of the uptake and
acetylation of labeled choline by toxin-treated P2 fractions. More
significantly, notexin inhibited the release of this newly synthesized
transmitter. These effects were found to be dependent on the dose of the
toxin and the time of exposure of the P2 fraction to notexin. Longer
exposure to notexin or experiments involving resuspension of
notexin-treated P2 fractions appeared to result in considerable lysis of
the transmitter-containing particles. Thus, notexin may alter acetylcholine
compartmentation in the nerve ending and thereby affect acetylcholine
synthesis.