The neuromuscular junction of a pulmonate mollusc. I. Ultrastructural study

BARRANTES FJ

Z Zellforsch

Zeitschrift für Zellforschung und Mikroskopische Anatomie

Lugar: Viena; Año: 1970 vol. 104 p. 205 - 212

The innervation of muscle cells in the posterior (optical) tentacle of the Argentine slug Vaginula soleiformis D´Orbigny was studied with the electron microscope. The neuromuscular junctions showed some degree of complexity regarding the apposed membranes of the pre- and postsynaptic elements in comparison to other molluscan species so far studied. Two populations of granulated vesicles with mean diameters of 855 and 1,190 Å respectively, in addition to clear synaptic vesicles, were observed. Since these two populations occur in separate nerve endings, which also show other distinctive morphological features, the existence of two different types of neuromuscular junctions is postulated.