title: THYSANURAN MEDIAN FRONTAL ORGAN: ITS STRUCTURAL RESEMBLANCE TO PHOTORECEPTORS.
abstract: The median frontal organ of Thermobia domestica (Packard) and the median ocellus of Tricholepidion gertschi Wygodzinsky were compared with respect to location, innervation, and fine structure. The data suggest that the two organs are homologous. Elementary neurosecretory granules were not found in the median frontal organ, but multivesicular bodies are present in both the frontal organ and ocellus
mesh_terms: D000818:Animals; D004583:Electrons; D004702:Endocrine Glands; D007313:Insecta; D008853:Microscopy; D008854:Microscopy, Electron; D009489:Neurosecretion; D012106:Research; D011984:Sensory Receptor Cells
keywords: ENDOCRINE GLANDS; EXPERIMENTAL LAB STUDY; INSECTS; MICROSCOPY, ELECTRON; NEUROSECRETION; RECEPTORS, NEURAL