ZfN: Search Results

1	Author	PeterH. Ochstrate	Requires cookie*
	Title	Photoresponses from Cells in the Fly's Eye which are not Visual Cells
	Abstract	It is shown that light elicits distinct responses from cells in the fly's eye which are different from photoreceptors. These cells are designated as "slow cells" because o f their sluggish response characteristics. Like the visual cells the slow cells depolarize upon light stim ulation, but the time course o f their responses is clearly different from that o f the photoreceptors. Furtherm ore, the intensity necessary to evoke a given response amplitude is considerably higher in slow cells than in photoreceptors. Several lines of evidence indicate that the slow cell response is caused by light absorption through the visual pigment rhodopsin in the peripheral photoreceptors R l —6. The slow cells are electrically coupled among each other, as dem onstrated by application of local light stimuli and injection of the fluorescent dye Lucifer Y ellow . The identity o f the slow cells and the mechanism o f response generation are discussed.
	Reference	Z. Naturforsch. 44c, 867 (1989); received May 17/June 13 1989
	Published	1989
	Keywords	V ision, Fly, Photoreceptor, R hodopsin, Pigment Cells
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	TEI-XML for	default:Reihe_C/44/ZNC-1989-44c-0867.pdf
	Identifier	ZNC-1989-44c-0867
	Volume	44

2	Author	Cole Gilbert	Requires cookie*
	Title	Membrane Conductance Changes Associated with the Response of Motion Sensitive Insect Visual Neurons
	Abstract	Intracellular recordings and impedance measurements from directionally-selective visual in terneurons o f the lobula plate o f flies show that during m otion, transmembrane conductance increases during both depolarizing responses to preferred directions and hyperpolarizing re sponses to anti-preferred directions. This provides direct evidence that these interneurons are postsynaptic to two separate populations o f excitatory and inhibitory input elements.
	Reference	Z. Naturforsch. 45c, 1222—1224 (1990); received April 18/September 17 1990
	Published	1990
	Keywords	Fly, Visual M otion, Interneuron, Conductance Change
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	TEI-XML for	default:Reihe_C/45/ZNC-1990-45c-1222.pdf
	Identifier	ZNC-1990-45c-1222
	Volume	45

3	Author	Ulrich Schraermeyer, Hennig Stieve, Michael Rack	Requires cookie*
	Title	Cytochemical Localization of Guanylate and Adenylate Cyclase in Photoreceptor Cells of the Fly
	Abstract	In photoreceptor cells o f invertebrates light triggers an enzyme cascade in which the phos-phoinositide pathway is crucially involved. Likewise, there is growing evidence of an impor tant role of cyclic nucleotides, too. To localize these enzymes able to catalyze the formation of cGM P and cAMP, the spatial distribution of guanylate cyclase (EC 4.6.1.2) and adenylate cyclase (EC 4.6.1.1) was determined in photoreceptor cells of the fly. In photoreceptor cells of the blowfly (Calliphora erythrocephala), the electron dense reaction product o f guanylate cyclase was found within the phototransducing region, the rhabdomeral microvilli and in the mitochondria. Staining was also observed throughout the cytoplasm of the microvilli. With the same cytochemical method, reaction product for adenylate cyclase was found on the tips of the photosensory membrane, and not in the cytoplasm o f the rhabdomeral microvilli. The results presented here further argue for an important role of one or possibly two cyclic nucleotides in the photoreceptor cells, and possibly in the process o f phototransduction of in vertebrates.
	Reference	Z. Naturforsch. 50c, 695—6 (1995); received May 24/July 10 1995
	Published	1995
	Keywords	Electron Microscopy, Guanylate Cyclase, Adenylate Cyclase, Photoreceptor, Fly
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	TEI-XML for	default:Reihe_C/50/ZNC-1995-50c-0695.pdf
	Identifier	ZNC-1995-50c-0695
	Volume	50