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Volume 18 (1978)
- Issue 6 Pages 239-
- Issue 5 Pages 195-
- Issue 4 Pages 149-
- Issue 3 Pages 105-
- Issue 2 Pages 47-
- Issue 1 Pages 1-
Volume 18, Issue 3
Displaying 1-6 of 6 articles from this issue
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Kohtaro KAMINO1978 Volume 18 Issue 3 Pages 105-119
Published: May 25, 1978
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSPhysiologists and biophysicists have long been interested in optical changes coupled with neuron or muscle activity. Although the mechanism of optical changes is not well understood, it has become clear that many of optical changes are associated with changes in membrane potential. Thus, it was suggested that these optical signals, can in principle, be used to monitor the membrane potential. This application has been made more feasible recently by the finding that certain merocyanines, cyanines, and oxonols show large signals in fluorescence and/or absorption during action potentials in squid axons. With these dyes, changes in optical properties that were linearly related to membrane potential were found. The signal-to-noise ratios in squid axons may be very large (-100:1).
Quite recently, it became clear that the optical method of measuring membrane potential was a powerful tool for systems where, for reasons of scale, topology, or complexity, the use of microelectrodes would be inconvenient or impossible. Systems studied thus far include T-system and/or sarcoplasmic reticulum of muscle, invertebrate ganglion, and suspensions of cells and subcellular organelles.
This article first emphsized the optical changes associated with membrane potential while optical monitoring of membrane potential was subsequently reviewed.View full abstractDownload PDF (1939K) -
Hiroyuki OHSHIMA, Toshio MITSUI1978 Volume 18 Issue 3 Pages 120-129
Published: May 25, 1978
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSLong-range interaction between membranes in water is discussed along the line of the theory presented by the writers (J. Colloid Interface Sci. 63, 525 (1978)). Explanation is given on the phenomena reported by Inoko et al. (Biochim. Biopnys. Acta 413, 24 (1975)): there appear the four states I, II, III, and IV in the dipalmitoyl lecithin/water systems by addition of CaCl2 with a hysteresis in the I-II transition and the three states I, III, and IV in MgCl2 solutions. Calculated periods of the lamellar phase are in fairly good agreement with experimental data. Inter-membrane interactions are effective beyond 100Å-260Å in suitable conditions. There seems to be a rigid hydration layer with the thickness of about 11Å on the dipalmitoyl lecithin membrane at room temperatures. Discussion is made on ion adsorption on the membrane surface.View full abstractDownload PDF (479K) -
1978 Volume 18 Issue 3 Pages 129a
Published: 1978
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSDownload PDF (35K) -
1978 Volume 18 Issue 3 Pages 129b
Published: 1978
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSDownload PDF (35K) -
Patchiness and Bifurcation TheoryMasayasu MIMURA1978 Volume 18 Issue 3 Pages 130-136
Published: May 25, 1978
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSIt has been observed that plankton displays spatial heterogeneity (patchiness) even though its environment appears homogeneous. As a model mechanism to explain this phenomenon, an interaction model is proposed which is in a prey-predator relationship. The model considered here is a generalized Lotka-Volterra system with diffusion. The results show that perturbations caused by fluctuations give rise to patchiness after long time: it depends on certain biological factors.
A mathematical tool is the theory of bifurcation for partial differential equations.View full abstractDownload PDF (311K) -
1978 Volume 18 Issue 3 Pages 141-144
Published: May 25, 1978
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSDownload PDF (265K)
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