These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The effects of alpha-latrotoxin of black widow spider venom on synaptosome ultrastructure. A morphometric analysis correlating its effects on transmitter release.
    Author: Watanabe O, Meldolesi J.
    Journal: J Neurocytol; 1983 Jun; 12(3):517-31. PubMed ID: 6875622.
    Abstract:
    The morphological effects of alpha-latrotoxin, the major component of black widow spider venom, were studied quantitatively in a crude synaptosome fraction (prepared from rat brain cortices) which was incubated at 37 degrees C for 10 min in Ringer solutions. Two toxin concentrations were employed, one causing a very large stimulation of transmitter release (approximately 65% and approximately 43% release of [3H]noradrenaline from preloaded synaptosomes, with and without Ca2+ in the incubation buffer), the other 50-60% as active. Incubated synaptosomes, fixed in suspension with aldehydes, were evenly dispersed in agarose before embedding, to assure randomized sampling in the subsequent morphometric analysis. In all the experimental conditions investigated, alpha-latrotoxin treatment caused a significant decrease in the density (number/unit area) of synaptic vesicles in synaptosome profiles. Such an effect was dose-dependent and partially Ca2+-dependent, in good agreement with the data on transmitter release. At high toxin concentration a moderate increase of synaptosome volume and surface area was observed, both with and without Ca2+. Mitochondrial swelling appeared only in synaptosomes treated in Ca2+ containing medium. These effects of alpha-latrotoxin are similar to those described previously at the neuromuscular junction. Thus, the toxin might be a tool of general use for studying vertebrate synapses.
    [Abstract] [Full Text] [Related] [New Search]