FMRFamide-like and allatostatin-like immunoreactivity in the lateral heart nerve of Periplaneta americana: colocalization at the electron-microscopic level.
Both allatostatin immunoreactivity (AS-IR) and FMRFamide immunoreactivity (FMRFa-IR) have been demonstrated light-microscopically in the lateral heart nerve of Periplaneta americana. The identical labeling of some fibers suggests the coexistence of the two antigens. Electron-microscopically, six granule types in the peripheral part of the lateral heart nerve can be distinguished according to their size and density (types 1-6). These granule types can be subdivided immunocytochemically by means of a new mirror-section technique. Granules of types 4 and 5 always exclusively show FMRFa-IR. In the populations of fibers containing granules of types 1 and 6, axon profiles can be found that contain granules colocalizing FMRFa-IR and AS-IR. Other axon profiles of these populations only contain immunonegative granules of the same ultrastructure. Granules of type 2 can be differentiated immunocytochemically in three forms in the same section: In some fibers, they are nonreactive; in other fibers of the same section, they show FMRFa - IR, whereas in a third fiber type, granules show AS - IR. Finally, granules of type 3 can be observed with FMRFa-IR. In other fibers, they occur with the same ultrastructure but exhibit no immunoreactivity. Two soma types occur in the lateral heart nerve. Soma type I is characterized by the production of electron-dense granules that show FMRFa-IR. Type II is in close contact with various fibers, forming different types of axosomatic synapses, hitherto unknown in Insecta.
Ude
J
J
Institute of General Zoology and Animal Physiology, Department of Electron Microscopy, Friedrich Schiller University, Erbertstrasse 1, D-07743 Jena, Germany.
Agricola
H
H
D000595:Amino Acid Sequence; D000818:Animals; D019835:FMRFamide; D006321:Heart / Q000294:innervation; D006727:Hormone Antagonists / Q000032:analysis*; D007447:Invertebrate Hormones / Q000032:analysis* / Q000037:antagonists & inhibitors; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000032:analysis*; D018377:Neurotransmitter Agents / Q000032:analysis*; D010526:Periplaneta / Q000033:anatomy & histology / Q000737:chemistry*
D006727:Hormone Antagonists; D007447:Invertebrate Hormones; D009479:Neuropeptides; D018377:Neurotransmitter Agents; C076523:allatostatin; D019835:FMRFamide