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Volume 14 (1974)
- Issue 6 Pages 239-
- Issue 5 Pages 183-
- Issue 4 Pages 135-
- Issue 3 Pages 93-
- Issue 2 Pages 45-
- Issue 1 Pages 1-
Volume 14, Issue 3
Displaying 1-4 of 4 articles from this issue
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Yuji KITO, Toshiaki HAMANAKA1974 Volume 14 Issue 3 Pages 93-105
Published: May 25, 1974
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSRecent studies in visual processes are summarized with special reference to the chromophore and visual pigments in solution and membrane.
Absorption spectrum of visual pigment is explained on the basis of protonated Schiff base linkage between the chromophore, 11-cis retinal and opsin, the protein moiety.
Action of light in vision is to isomerize the 11-cis retinal to all-trans configuration. The subsequent structural change in protein moiety induces an amplified change in ion permeability across the outer segment membrane.
Thus the outer segment is the actual site of visual excitation. Electron microscopy, all type of light spectroscopy and low angle X-ray analysis have revealed a striking degree of ordering of the outer segment membranes and of orientation of the visual pigments.View full abstractDownload PDF (1306K) -
1974 Volume 14 Issue 3 Pages 105
Published: 1974
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSDownload PDF (42K) -
Mitsuru TAKATA1974 Volume 14 Issue 3 Pages 106-117
Published: May 25, 1974
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSIn order to clarify the synaptic organization of somatosensory cortical neurons (SI neurons) in a cat, this experiment focused on the classification of SI neurons from the postsynaptic potentials evoked by skin volley of contralateral forlimb. Out of 100 explored neurons, many SI neurons showed the EPSP-IPSP sequency of potentials by skin volley. Especially, a long-lasting hyperpolarization evoked by skin afferents was remarkable on SI neurons. For example, SI neurons with 70mV spike height elicited the long duration of IPSP (200msec) with 15mV amplitude by skin volley. From the shift of equilibrium potential by Cl ion injection, ionic mechanism for IPSP on SI neuron was enhancement of Cl permeability on subsynaptic membrane. And it was speculated that the location of inhibitory synapse was on soma membrane, because the IPSP was sensitive to injected currents. Simultaneous recording on both VPL neuron extracellulary and SI neuron intracellulary was succeeded, and it was speculated that a VPL neuron and a SI neuron played on the acceptance of sensory information as a physiological unit.
This experiments were done with Dr. S. Andersson and Dr. I. Lehtinen in sweden.View full abstractDownload PDF (758K) -
Sohei KONDO1974 Volume 14 Issue 3 Pages 118-126
Published: May 25, 1974
Released on J-STAGE: May 25, 2009
JOURNAL FREE ACCESSRecent knowledge of DNA repair is reviewed in perspective with emphasis on Escherichia coli. Enzymatic phtoreactivation is the simplest and the most general among the three major DNA repair systems. Excision repair is also common from microorganisms to human and yet its molecular mechanism is not universal. Tolerance repair, i.e., post-replication repair, is effective for the widest variety of DNA damage and rather different between lower and higher forms. From these characteristics, it is proposed that DNA repair mechanisms evolved in the order of photoreactivation, excision repair and tolerance repair after the primary living systems were created by solar ultraviolet.View full abstractDownload PDF (1525K)
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