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R Higashi

Publications and source records attributed to R Higashi.

35 records · Page 2Linked to original sources
PubMed1982

Regional difference in fenestration of choroidal capillaries in Japanese monkey eye.

The fenestration of the endothelial cells of the choroidal capillaries in the periphery, posterior pole and macular region of the eyeball was studied comparatively by the freeze-fracture technique and morphometric analysis. Fenestrations in the P face appeared as circular or ovoid, vallate papillae, whereas those in the E face appeared as craters. The central know of the diaphragm, which is composed of a cluster of particles, could be observed in some fenestrations. The average diameter of fenestrations was 95.5 +/- 9.9 nm in the periphy, 73.2 +/- 4.8 nm in the posterior pole and 79.3 +/- 4.5 nm in the macular region. Among these three areas, the difference in diameter of fenestrations was significant (P less than 0.01). The average number of fenestrations per 1 micron2 was 32.0 +/- 4.4 in the periphery 39.3 +/- 2.5 in the posterior pole and 45.0 +/- 2.6 in the macular region. The difference in the density of fenestrations was significant (P less than 0.01) between the periphery and the macular region. The regional difference in the density of fenestration may indicate the functional difference of the relating retinal portion.

Animals↗
PubMed1980

Mesaxonal membrane junction of myelinated nerve in the central and peripheral nervous system.

Cell junction of the myelinated nerve mesaxon in the sciatic nerve and spinal posterior funiculus of rabbits and rats was examined by the freeze-fracture method. In replicas of fractured specimens, the cell junctions were the tight junction which was composed of parallel arrays of membrane particles. The rows of particles were straight or gently undulating along the long axis of the fibers. Occasional interconnections were formed among these rows. In the external mesaxon, the tight junctional particles in the central nerve were arranged in 3 to 6 lines and well developed more than those of the peripheral nerve consisting of 1 to 2 linear arrangement of particles. "Intramyelinic" tight junctions were well developed as well as some arrays of linear arrangement of particles in the central nerve. However, the junctions were poor and fragmental in the peripheral nerve. Functional meanings of the difference of the mesaxonal and intramyelinic tight junctions between the central and peripheral myelinated nerve are discussed.

Animals↗