Ultrastructural localization of unique neurosecretory granules in the corpora cardiaca of the stable fly, Stomoxys calcitrans, and the tsetse fly, Glossina morsitans

Ultrastructural analysis of the corpora cardiaca of the stable fly, Stomoxy s calcitrans, and the tsetse fly, Glossina morsitans, revealed the presence of elementary neurosecretory granules (ENG) unique to the intrinsic neuros ecretory cells (INC) of these species. In addition to electron-dense sphere s, the INC of the corpus cardiacum of the stable fly contain electron-dense angular granules, either square or rectangular in shape, while the INC of the tsetse fly contain electron-dense spindle-shaped ENG. The distinctive g ranules of these INC can be traced within nerves to their sites of storage and release, eliminating the need for labeling with artificial probes. Alth ough the INC of the corpus cardiacum of most species have been found to be fuchsinophilic, neither the INC of the stable fly nor the tsetse fly are al dehydefuchsinophilic. These peptigenic cells offer neuroendocrinologists a unique opportunity to study the physiology and biochemistry of neurosecreto ry cells. J. Morphol. 240:155-168, 1999. Published 1999 Wiley-Liss, Inc.