Ultrastructural Detection of Secretory Function of the Pineal Organ of the Ice Goby, Leucopsarion petersi
Year: 1983
Type: article
Abstract: The pineal organ of the ice goby, Leuoopsarion petersi, was examined electron microscopically in order to search for indications of its secretory function.The pineal of the fish is a compact organ which is mainly composed of centrally located photoreceptor cells and peripherally arranged supportive cells.Photoreceptor cells existing in the middle and proximal parts of the pineal end-vesicle are of a typical structure with well-organized outer segments and denser cytoplasm, while those distributed in the distal part are modified to have irregular outer segments and clearer cytoplasm.The modified photoreceptor cells contain slightly dilated rough endoplasmic reticulum and dense-cored vesicles of two different sizes in the perinuclear cytoplasm.Dense-cored vesicles of the smaller size-class are scattered throughout the perinuclear cytoplasm, while those of the larger size-class are always found to be associated closely with the rough endoplasmic reticulum, often forming peculiar structures consisting of several layers of parallel granulated cisternae accompanied by dense-cored vesicles.The cytoplasm of supportive cells is characteristically packed with abundant tubular cisternae of the smooth endoplasmic reticulum.Electron-dense material is accumulated in some interstices among the microvilli of the supportive cells.Unmyelinated nerve fibers running along the periphery of pineal end-vesicle sometimes contain both clear and dense-cored vesicles.Furthermore, nerve terminals containing both clear and dense-cored vesicles of similar sizes to those found in the nerve fibers occur bordering on the basal processes of photoreceptor cells.The results may suggest that the pineal organ of the ice goby has not only a photosensory function but also a secretory function.
Authors: Fuminari Ito, Hiroya Takahashi
Language: English
Subfield: Endocrine and Autonomic Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W329337121