Biomaterial Database

The tight epithelium of the Mongolian gerbil subcommissural organ as revealed by freeze-fracturing. 1979

J K Madsen, and K Møllgård

Examination of neonatal Mongolian gerbil subcommissural organ (SCO) by freeze-fracture electron microscopy reveals that the epithelial layer (the ependyma) possesses distinctive and very complex tight junctions which connect the apical portions of adjacent ependymal cells. The tight junction network of the Mongolian gerbil is more extensive neonatally than in the adult, and is in general, more conspicuous than in other animal species. The consistent finding of such very complex tight junctions at the interface between the C.S.F. and the SCO suggests that the SCO ependyma, at least in neonatal Monglian gerbils, might function as a tight epithelium with an ability to maintain steep solute gradients and high potential differences. The sealing-off of the SCO towards the C.S.F. (the C.S.F.--SCO barrier) and the effective blood-brain barrier in the organ (the blood-SCO barrier) might well be of functional significance, perhaps in relation to mechanisms involved in the control and/or detection of the stability of the internal environment of the brain.

UI	MeSH Term	Description	Entries
D007365	Intercellular Junctions	Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)	Cell Junctions,Cell Junction,Intercellular Junction,Junction, Cell,Junction, Intercellular,Junctions, Cell,Junctions, Intercellular
D008297	Male		Males
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
D004805	Ependyma	A thin membrane that lines the CEREBRAL VENTRICLES and the central canal of the SPINAL CORD.	Ependymas
D005260	Female		Females
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
D005849	Gerbillinae	A subfamily of the Muridae consisting of several genera including Gerbillus, Rhombomys, Tatera, Meriones, and Psammomys.	Gerbils,Jird,Meriones,Psammomys,Rats, Sand,Gerbil,Jirds,Merione,Rat, Sand,Sand Rat,Sand Rats
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
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
D013351	Subcommissural Organ	Ependymal derivative located at the junction of the THIRD VENTRICLE and the CEREBRAL AQUEDUCT; and the SOMATOSTATIN SECRETING CELLS.	Organ, Subcommissural,Organs, Subcommissural,Subcommissural Organs