Synaptic vesicles in freeze-etched electric tissue of <i>Torpedo</i>

Abstract

Abstract The electric organs of the elasmobranch, Torpedo, are composed of stacks of hexagonal cells, called electroplaques, each of which is several millimetres in diameter, but only 5 to 10 /xm thick. The ventral surface of each cell is known to be richly innervated by cholinergic nerve terminals (Feldberg &amp; Fessard 1942; Sheridan 1965; Grundfest 1967; Israel &amp; Gautron 1969). We have taken advantage of the high density of innervation of this tissue, and of the fact that freeze-etching readily reveals membrane surfaces (Moor &amp; Mühlethaler 1963), to examine contacts between the synaptic vesicles and the presynaptic membranes of these nerve terminals (Nickel &amp; Potter 1970).