Nerve Impulse
نویسنده
چکیده
and are on adrenalectomy in diabetes, neurophysiological control of ACTH secretion, and hypertension. The volume is a unique type of bibliography arranged according to author and major and minor sub-groupings of the subject matter as well as listings of authors by serial numbers and may well serve as a model for other bibliographies. The critical reviews and comments add to the total bibliography in that they indicate to some extent the relative value given some of the references cited. The receptor organs, which are the gate-keepers of one's sensorium, were for a long time the "forgotten men" of neurophysiology. The appearance of the present volume is another testimonial that they are now achieving "union" status. The book contains three presentations, the first by George Wald on the rods and cones of the eye, the next by Hallowell Davis on the receptor apparatus of the internal ear, and the last by Yngve Zotterman on thermal receptors. It brings together a great number of fascinating new developments that otherwise might be lost sight of for a long while in specialized journals. Wald deals successively with the anatomy of the rods, the biochemistry of visual processes, and the in vivo and in vitro correlation of the adsorption spectra of rhodopsin and iodopsin. In conclusion he presents a model which suggests how one quantum of light, through the bleaching of one molecule of rhodopsin and the release of two to three sulfhydryl groups, might set off a chain reaction resulting in nervous excitation. Davis, after a brief review of the anatomy of the inner ear, sets forth ar intriguing explanation, backed up by compelling evidence, of how the energy of sound is transformed into electrical energy that in turn receives sufficient amplification to excite terminals of the cochlear nerve. In the process, he draws heavily on the beautifully executed experiments of Bekesy, who appears to have achieved almost the penultimate in microscopic techniques. He concludes by showing records of action potentials from single fibers of the cochlear nerve which Tasaki recorded with glass micro-electrodes having an outside diameter of 0.2,u. Such are the technical advances that have at last made possible a refined analysis of receptor mechanisms. As practically nothing is known about the anatomy of the thermal receptors, Zotterman is required to infer the nature of their activity on the basis of the impulses they trigger in the nerve fibers. He makes the …
منابع مشابه
Evaluation of the effect of dendritic branching on signal processing in hippocampus pyramidal cells
Since branching region of an active nerve fiber is an abrupt widening of the structure, two concepts emerge: first, the stimulating current must be sufficient to raise the outgrowing fibers above the thresh¬old, and secondly, the stimulating current will be divided in proportion to the characteristic admittance of the branches. On the other hand, blocking of the nerve impulse in this region is ...
متن کاملEvaluation of the effect of dendritic branching on signal processing in hippocampus pyramidal cells
Since branching region of an active nerve fiber is an abrupt widening of the structure, two concepts emerge: first, the stimulating current must be sufficient to raise the outgrowing fibers above the thresh¬old, and secondly, the stimulating current will be divided in proportion to the characteristic admittance of the branches. On the other hand, blocking of the nerve impulse in this region is ...
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ورودعنوان ژورنال:
- The Yale Journal of Biology and Medicine
دوره 27 شماره
صفحات -
تاریخ انتشار 1954