4-Ammopyridine-induced ultrastructural alterations of pinched-off nerve terminals from rat cerebral cortex

A. Mihály, D. Ágoston

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Pinched-off nerve terminals (synaptosomes) from rat cerebral cortex were depolarized with 60 mM KCl and treated with 20 mM 4-aminopyridine in order to evaluate ultrastructural alterations. The empty presynaptic terminals were counted and their number was given as a percentage of the normal terminals. The proportion of empty terminals increased from 10.47±1.56% to 32.45±1.88% (P < 0.001) following treatment with 20 mM 4-aminopyridine. This effect of 4-aminopyridine depended on the presence of Ca++ in the incubation medium. The results are discussed in terms of facilitation by 4-aminopyridine of exocytotic transmitter release. We think that the increase of the empty synaptosomes was due to the exhaustion or inhibition of the synaptic vesicle recycling mechanism.

Original languageEnglish
Pages (from-to)385-389
Number of pages5
JournalExperimental brain research
Issue number2
Publication statusPublished - Mar 1 1984



  • 4-Aminopyridine
  • Exocytosis
  • Recycling
  • Synaptosome
  • Ultrastructure

ASJC Scopus subject areas

  • Neuroscience(all)

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