Biomaterial Database

Horizontal-cell gap junction in the goldfish retina: area and density of particles as revealed by complementary freeze replicas. 1991

H Washioka, and H Watanabe, and K Negishi, and A Tonosaki

Department of Anatomy, Yamagata University School of Medicine, Japan.

Aiming at a morphological evaluation of horizontal cell gap junctions under intraocularly injected dopamine and 6-OH-dopamine influences as compared with those in the light and dark periods, the percentage of the junctional areas was computed by planimetry, and the distribution density of connexon particles by visual counting, on complementary freeze-replica electron micrographs. The outer plexiform layer was tentatively divided into the external-horizontal-somatic, intermediate-mixed-fibrous and internal-axon-terminal sublayers. The total number of connexon particles per cell seemed relatively unchanged, because the density of the particles was lower in the light period and after the dopamine treatment than in the dark and after the 6-OH-dopamine treatment; the percentage of the junctional area was conversely greater in the former than in the latter. The mode of response of the gap junction was presumed to occur in parallel with each of the sublayers after the chemical interference.

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
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
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
D006054	Goldfish	Common name for Carassius auratus, a type of carp (CARPS).	Carassius auratus
D006892	Hydroxydopamines	Dopamines with a hydroxy group substituted in one or more positions.	Hydroxydopamine
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
D016627	Oxidopamine	A neurotransmitter analogue that depletes noradrenergic stores in nerve endings and induces a reduction of dopamine levels in the brain. Its mechanism of action is related to the production of cytolytic free-radicals.	6-Hydroxydopamine,6-OHDA,Oxidopamine Hydrobromide,Oxidopamine Hydrochloride,6 Hydroxydopamine,Hydrobromide, Oxidopamine,Hydrochloride, Oxidopamine