Accession Number : ADA290637

Title :   Colocalization of Calcium Entry and Exocytotic Release Sites in Adrenal Chromaffin Cells.

Descriptive Note : Technical rept. Oct 94-Jan 95,

Corporate Author : NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY

Personal Author(s) : Robinson, Iain M. ; Finnegan, Jennefer M. ; Monck, Jonathan R. ; Wightman, R. M. ; Fernandez, Julio M.

PDF Url : ADA290637

Report Date : 13 JAN 1995

Pagination or Media Count : 24

Abstract : "Snapshot" images of localized Ca2+ influx into patch-clamped chromaffin cells were captured using a recently developed pulsed-laser imaging system. Transient opening of voltage-sensitive Ca2+ channels gave rise to localized elevations of Ca that had the appearance of either "hotspots" or partial rings found immediately beneath the plasma membrane. When the Ca2+ imaging technique was employed in conjunction with flame-etched carbon-fiber electrodes to spatially map the release sites of catecholamines, it was observed that the sites of Ca2+ entry and catecholamine release were co-localized. These results provide functional support for the idea that secretion occurs from "active zone"-like structures in neuroendocrine cells.

Descriptors :   *CALCIUM, *CATECHOLAMINES, TRANSIENTS, OPENING(PROCESS), CHEMICAL PROPERTIES, CELLS, PLASMAS(PHYSICS), SITES, RELEASE, MEMBRANES, HOT SPOTS, RINGS, NEUROLOGY, CHROMIUM COMPOUNDS, ADRENAL GLANDS, ENDOCRINE GLANDS.

Subject Categories : Organic Chemistry
      Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE