Biomaterial Database

Ependymal cells variations in the central canal of the rat spinal cord filum terminale: an ultrastructural investigation. 2013

A Mitro, and K Gallatz, and M Palkovits, and A Kiss

Slovak Academy of Sciences, Bratislava, Slovak Republic.

OBJECTIVE The ependymal cells, considered today as an active participant in neuroendocrine functions, were investigated by electron microscopy in the central canal of the lowest spinal cord, the filum terminale (FT), in adult rats. In this area of the spinal cord, the central canal is covered by a heterogeneous population of ependymal cells. The aim of the present work was to compare the regional features of the ependymal cells in two different parts of the FT with a special regard to their ultrastructure. METHODS Two parts of the FT were selected for the ultrastructural observations: the rostral (rFT) and the caudal (cFT) ones. The rTF was removed at the level of the immediate continuation of the conus medullaris, while the cFT 30 mm further caudally. After formaldehyde fixation, the spinal cord was removed and cut into small blocks for electron microscopic processing. The material was embedded into durcupan, contrasted with uranyl acetate, lead citrate as well as osmium tetroxide, and investigated under JEOL 1200 EX electron microscope. RESULTS In the rFT, the ependymal lining is pseudostratified and one-layered in the cFT, whereas the shape of the ependymal cells may vary from cuboidal to flatten in the rostro-caudal direction. The basal membrane of many ependymal cells possesses deep invaginations, so called "filum terminale labyrinths". Many neuronal processes occur in the pericanalicular neuropil. In contrast to the rFT, the cFT is less rich in the neuropil particles. Some of the ependymal cells concurrently reach both the intracanalicular and extracanalicular cerebrospinal fluid (CSF), thus they may represent a new variant of the ependymal cells designated as "bridge cells of the FT". CONCLUSIONS The present data indicate that the FT ependymal cells exhibit clear differences in anatomy as well as ultrastructure that may reflect their distinct functional activity. Therefore, observations presented here may serve for the better understanding of the physiological role of the individual ependymal areas in this special portion of the rat spinal cord.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009457	Neuroglia	The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.	Bergmann Glia,Bergmann Glia Cells,Bergmann Glial Cells,Glia,Glia Cells,Satellite Glia,Satellite Glia Cells,Satellite Glial Cells,Glial Cells,Neuroglial Cells,Bergmann Glia Cell,Bergmann Glial Cell,Cell, Bergmann Glia,Cell, Bergmann Glial,Cell, Glia,Cell, Glial,Cell, Neuroglial,Cell, Satellite Glia,Cell, Satellite Glial,Glia Cell,Glia Cell, Bergmann,Glia Cell, Satellite,Glia, Bergmann,Glia, Satellite,Glial Cell,Glial Cell, Bergmann,Glial Cell, Satellite,Glias,Neuroglial Cell,Neuroglias,Satellite Glia Cell,Satellite Glial Cell,Satellite Glias
D009490	Neurosecretory Systems	A system of NEURONS that has the specialized function to produce and secrete HORMONES, and that constitutes, in whole or in part, an ENDOCRINE SYSTEM or organ.	Neuroendocrine System,Neuroendocrine Systems,Neurosecretory System,System, Neuroendocrine,System, Neurosecretory,Systems, Neuroendocrine,Systems, Neurosecretory
D002420	Cauda Equina	The lower part of the SPINAL CORD consisting of the lumbar, sacral, and coccygeal nerve roots.	Filum Terminale,Equina, Cauda,Terminale, Filum
D003712	Dendrites	Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.	Dendrite
D004805	Ependyma	A thin membrane that lines the CEREBRAL VENTRICLES and the central canal of the SPINAL CORD.	Ependymas
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001369	Axons	Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.	Axon