Spontaneous quantal transmitter secretion from myocytes and fibroblasts: comparison with neuronal secretion

• DOI: 10.1523/jneurosci.15-04-02826.1995
• Publication Date: 2018-04-02T18:16:07Z
• Authors: R Girod; S Popov; J Alder; JQ Zheng; A Lohof; MM Poo
• Keywords: Neurons; 0301 basic medicine; Cytoplasm; Embryo, Nonmammalian; Patch-Clamp Techniques; Myocardium; Xenopus; Heart; Fibroblasts; Motor Endplate; Acetylcholine; Membrane Potentials; 03 medical and health sciences; Organ Specificity; Synapses; Animals; Quantum Theory; Calcium; Fura-2; Egtazic Acid; Cells, Cultured; Chelating Agents

When exogenous ACh is loaded into the cytoplasm of cultured amphibian myocytes and fibroblasts, cells undergo spontaneous quantal secretion, as detected by appearance pulsatile membrane currents in Xenopus which are manipulated contact with cells. These resemble many ways miniature endplate (MEPCs) observed at developing neuromuscular synapses formed on these myocytes. Analyses frequency, amplitude, time course suggests similarity cellular mechanisms involved packaging secretion quanta myocytes, neurons. The size packets released non-neuronal were found to be very similar neuronal quanta, thought result from exocytotic release synaptic vesicles. Moreover, kinetics discharged all three cell types comparable, although speed somewhat slower more irregular. neurons was decreased reducing cytosolic Ca2+ level enhanced activation protein kinase C phorbol ester, but fibroblasts unaffected both treatments. did show some sensitivity a rise after treatment ionophore. observations support hypothesis that basic machinery for transmitter operating derive ubiquitous mechanism used constitutive trafficking cells, differentiation involves expression additional unique components regulation secretion.