In:
European Journal of Neuroscience, Wiley, Vol. 9, No. 1 ( 1997-01), p. 140-150
Abstract:
The distribution of voltage‐sensitive elevations of the level of Ca 2+ in untreated SH‐SY5Y cells and cells that had been induced to differentiate with staurosporine was investigated by monitoring fura‐2 fluorescence in cell suspensions, and by using microfluorometry and quantitative fluorescence imaging on cell bodies and on cellular processes. Cell bodies of both types of cells displayed small Ca 2+ elevations, which were composed of transient and sustained components. Elevations were partially sensitive to the L‐ and N‐channel blockers nifedipine (1 μM) and ω‐conotoxin GVIA (100 nM) respectively. Up to ten times higher Ca 2+ elevations were observed in varicosities of treated cells than in cell bodies of treated and untreated cells. These elevations were insensitive to compounds known to release Ca 2+ from intracellular stores. Elevations of Ca 2+ were sustained, and they were insensitive to 5 pM nifedipine, 100 nM ω‐agatoxin IVA and 100 nM ω‐conotoxin GVIA, and partially sensitive to 2 pM ω‐conotoxin GVIA, indicating predominance of non‐L‐type, non‐N‐type, non‐P‐type channel activity. The intracellular localization of neuropeptide Y, a marker of differentiation in these cells, was also investigated by fluorescence immunocytochemistry. Varicosities of treated cells displayed marked fluorescence when viewed in a confocal microscope. These findings show that the varicosities of staurosporine‐treated cells exhibit some of the functional properties of nerve terminals. The varicosities resemble boutons en passant nerve endings and they seem to express Ca 2+ channels different from those in the cell body.
Type of Medium:
Online Resource
ISSN:
0953-816X
,
1460-9568
DOI:
10.1111/ejn.1997.9.issue-1
DOI:
10.1111/j.1460-9568.1997.tb01362.x
Language:
English
Publisher:
Wiley
Publication Date:
1997
detail.hit.zdb_id:
2005178-5
SSG:
12
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