Imaging of L-type Ca2+ channels in olfactory bulb neurones using fluorescent dihydropyridine and a styryl dye.
We have imaged the fluorescence of dihydropyridine-Bodipy (fDHP) in cultured olfactory bulb neurones in order to investigate the subcellular distribution of L-type calcium channels in these neurones. The neurones were stained with both fDHP and the voltage-sensitive styryl dye RH414. The fluorescence emission maxima of these dyes were in the green and red ranges of the spectrum, respectively, and were recorded by the 2 photomultiplier channels of a laser scanning microscope. The fDHP images were ratioed with the RH414 images taken simultaneously. The resulting ratio images revealed the spatial distribution of the surface density of L-type calcium channels. This density was highest on somata, in particular at the base of dendrites, and decreased with the distance from this maximum. Two classes of dendritic L-type channel distributions were observed: one with a homogeneously low density and another one with a characteristic gradient of the L-type channel density along proximal dendrites. This subcellular localization of L-type calcium channels is discussed in the light of specific functional roles.
Physiologisches Institut, Universität Göttingen, Germany.
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D
Schild
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Geiling
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Bischofberger
D000818:Animals; D001896:Boron Compounds; D002120:Calcium Channel Agonists; D015220:Calcium Channels / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism; D005456:Fluorescent Dyes; D019044:Image Cytometry / Q000379:methods*; D018613:Microscopy, Confocal; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D009830:Olfactory Bulb / Q000166:cytology* / Q000378:metabolism*; D011725:Pyridines; D011726:Pyridinium Compounds; D013347:Subcellular Fractions / Q000502:physiology; D014982:Xenopus laevis
D001896:Boron Compounds; D002120:Calcium Channel Agonists; D015220:Calcium Channels; D005456:Fluorescent Dyes; D011725:Pyridines; D011726:Pyridinium Compounds; C097266:dihydropyridine-BODIPY; C054158:RH 414