Search Results - (Author, Cooperation:B. Minke)
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1Latest Papers from Table of Contents or Articles in PressStaff View
Publication Date: 2011-03-12Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Drosophila Proteins/genetics/metabolism/*physiology ; Drosophila melanogaster/genetics/*physiology ; Larva/physiology ; Light ; Mutation ; Photoreceptor Cells, Invertebrate/physiology ; Rhodopsin/chemistry/genetics/*physiology ; TRPC Cation Channels/metabolism ; Temperature ; *ThermosensingPublished by: -
2Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] Many photoreceptor cells in invertebrates have a dual-peak spectral sensitivity. Evidence is presented that in fly photo-receptors the ultraviolet peak is due to a photostable pigment that absorbs light quanta and transfers the energy to the blue-absorbing visual ...Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 0167-4889Keywords: Calcium ion, intracellular store ; Light adaptation ; Protein kinase C ; Response inactivation ; Rhodopsin kinase ; Rhodopsin phosphataseSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: BiologyChemistry and PharmacologyMedicinePhysicsType of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesHardie, R. C. ; Peretz, A. ; Suss-Toby, E. ; Rom-Glas, A. ; Bishop, S. A. ; Selinger, Z. ; Minke, B.
[s.l.] : Nature Publishing Group
Published 1993Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] Another mutant showing behaviour similar to inaC is the transient receptor potential mutant (trp). In trp this phenotype, which we refer to as response inactivation , is thought to represent exhaustion of the excitatory process20'21, and in fact virtually all manifestations of light adaptation are ...Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1432-1106Keywords: Striate Cortex ; Monocular and Binocular Stimulations ; Neuronal Responses ; Local and Surface VEPs ; Latencies ; Phase Relationships ; Algebraic SummationSource: Springer Online Journal Archives 1860-2000Topics: MedicineNotes: Summary The post-stimulus-time histograms of single unit responses recorded extracellularly from simple and complex cells in the paralyzed cat's striate cortex were compared both with the averaged visual evoked potential (VEP) recorded with the same stainless steel microelectrode and with the averaged surface VEP recorded with a silver-ball electrode applied close to the locus of microelectrode penetration. Diffuse and patterned white light stimuli, projected on a tangent screen in front of the animal, were used monocularly and binocularly at an intensity range over 2.5 log units. The latencies of spike responses to contralateral stimuli were found on the average shorter than those to ipsilateral and generally equal to those following binocular stimulation. The reciprocals of latencies as function of log stimulus intensity of the surface VEPs had the same gradient as those from averaged unit responses. In recordings from any given cell, the spike discharges displayed a fixed phase relationship to the local and another to the surface VEP, but this was not necessarily identical in different cells. These discharges may be related to the negative and positive phases of both types of slow waves. The surface and local VEPs elicited by binocular diffuse light stimulation represent the algebraic summation of the VEPs produced by ipsi- and contralateral stimulations, which confirms and expands earlier studies. No algebraic summation was found in the spike response, the sum of the two monocular responses being in most cases larger than the binocular.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1432-1017Keywords: Visual pigment ; Diffusion ; Photoreceptor ; MembraneSource: Springer Online Journal Archives 1860-2000Topics: BiologyPhysicsNotes: Abstract Translational diffusion of pigment molecules in the disc membranes of amphibian rod outer segments is in the range of 10 Μ/10 s. Recently, Goldsmith and Wehner set an upper limit of 10 Μ/20 min to the diffusion in isolated formaldehyde-fixed rhabdoms of crayfish. We have now used the early receptor potential (ERP) to study the diffusion in intact, unfixed barnacle photoreceptors. The ERP from a cell fully adapted to blue light (most of the pigment in the rhodopsin state) was changed by 8–22% of its maximum change when the pigment in a 30 Μm spot was (almost) completely shifted to the metarhodopsin state by red laser adaptation. Further red illumination of the same spot 30 min later produced only a limited further change in the ERP (attributable to light scatter), showing that R had not migrated into the spot. It is concluded that the visual pigment diffuses by less than 30 Μ/30 min.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1432-1017Keywords: Musca photoreceptors ; Ruthenium red ; Ouabain ; Na+- andCa2+-gradientsSource: Springer Online Journal Archives 1860-2000Topics: BiologyPhysicsNotes: Abstract We found recently that illumination of white-eyed Musca photoreceptors following application of ruthenium red (RR), (a known inhibitor of Ca2+-uptake into intracellular organelles) induced a transient post-illumination-afterdepolarization (TA). We found that the TA depended strongly on Na+- and Ca2+-gradients across the cell membrane suggesting that it arose from activation of electrogenic Na+-Ca2+-exchange. Since the magnitude of the TA was dependent on the Na+-gradient, in this work we studied the effects of the Na+/K+-pump, which controls the Na+-gradient, on the TA. Increasing extracellular K+-concentration which largely increased pump activity also increased the TA. Application of 100 ΜM ouabain, for a short time, depressed the TA considerably without causing any noticeable effect on the resting or the receptor potential. Only after longer exposure to ouabain, when the TA was totally depressed, were the resting and receptor potentials abolished by only a few strong light flashes. Trains of strong light pulses either facilitated or inhibited the TA depending on the degree of increase in internal Ca2+-ions by light and on the activity of the Na+/K+-pump.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1432-0770Source: Springer Online Journal Archives 1860-2000Topics: BiologyComputer SciencePhysicsNotes: Abstract We analyze the kinetics of a pigment system with thermal and photochemical transitions among its states. The general mathematical description is obtained and is then specialized to systems with two stable states (states with negligible thermal outlets) in which the total amount of pigment is conserved. We describe the properties of the pigment state populations and of their kinetics in not-too bright lights. The wavelength dependence of the population distribution following saturating light is called the saturation spectrum. The populations are shown to relax to this saturation distribution exponentially with amount of light; the wavelength dependence of the relaxation constant is called the relaxation spectrum. The specialized description of the pigment kinetics is applied to the six-state, two-stable-state model of Minke et al. (1974) for the barnacle visual pigment. The immediate spur for this analysis was a problem which has recently become acute: That of deciding between a single bistable pigment system and two separate systems as the possible origin of various abnormally-shaped or nonmatching action or absorption spectra or wavelengthdependent response forms which have been observed in many invertebrate photoreceptors. We show that these two possibilities may be distinguished quite generally by saturation and relaxation measurements, and describe such measurements in the following article.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1432-0770Source: Springer Online Journal Archives 1860-2000Topics: BiologyComputer SciencePhysicsNotes: Abstract Using early receptor potential (ERP) measurements, we show that the bistable pigment in the barnacle photoreceptor behaves according to the conclusions of the preceding article (Hochstein et al., 1978): (1) The populations of both stable states approach their steady-state or “saturation” values under steady illumination exponentially with the same rate constant; the wavelength dependence of this rate constant is called the relaxation spectrum. — (2) The saturation values are independent of initial population and of light intensity; the wavelength dependence of the saturation population is called the saturation spectrum. — (3) The measured relaxation and saturation spectra agree with those calculated, by the theory of the preceding article, from the experimentally determined transition parameters of the pigment system. — We then demonstrate the applicability of relaxation and saturation measurements to the question of whether a single bi-stable pigment system serves, or two or more separate systems serve, as the origins(s) of the ERP and of other phenomena observed in the barnacle photoreceptor: The prolonged depolarizing afterpotential (PDA) and its depression and prevention (anti-PDA). By showing that the relaxation spectra for these phenomena match one another and that of the ERP, and that the same is true for the saturation spectra, we demonstrate that these phenomena originate from the same single bi-stable pigment system as the ERP.Type of Medium: Electronic ResourceURL: