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ELICITATION OF SPREADING DEPRESSION BY ROSE BENGAL PHOTODYNAMIC ACTION
Author(s) -
Netto Marialia,
MartinsFerreira Hiss
Publication year - 1989
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1989.tb04153.x
Subject(s) - rose bengal , action (physics) , rose (mathematics) , depression (economics) , bengal , cortical spreading depression , chemistry , psychology , biology , oceanography , physics , psychiatry , geology , horticulture , economics , macroeconomics , organic chemistry , migraine , quantum mechanics , bay
Abstract— Spreading depression refers to a slowly propagating depression of the ordinary electrical activity of the nervous tissue. It can be elicited by different types of physical or chemical non‐specific stimuli. Various evidences suggest that transient alterations of cell membranes are involved. For this reason, and considering the action of free radicals on cell membranes, the elicitation of the reaction by dye photoactivation has been investigated. Isolated chick retina superfused in the dark with Ringer solution was able to regularly exhibit spreading depression when submitted to 1 µ,M rose bengal pulse of 5 min in duration, followed by 2.1 10 4 to 4.2 times 10 4 Jm ‐2 light pulse. The phenomenon was monitored either by visual inspection of the light‐scattering milky wave that accompanies the reaction or by recording its characteristic slow voltage variation. The reaction was not triggered if the retina, superfused with the dye, was (a) maintained in the dark; (b) illuminated with red light (3.75 times 10 2 to 2.25 times 10 4 Jm ‐2 ), or (c) stimulated by white light but superfused with nitrogen‐saturated solutions. It is concluded that, under the present conditions, the elicitation of spreading depression is contingent on the photoactivation of rose bengal in the presence of oxygen.