CHANGES IN THE FORM AND RESPONSE OF THE NEURULA IN THE DEVELOPING OVUM OF WHITE LEGHORN

Autor: Kazuo Ogura, Susumu O'hata, Shuji Shinozuka
Rok vydání: 1963
Předmět:
Zdroj: The Japanese Journal of Physiology. 13:14-23
ISSN: 1881-1396
0021-521X
DOI: 10.2170/jjphysiol.13.14
Popis: Brief exponential shocks were delivered upon the fresh neurula developing from the ovum of a white leghorn incubated under optimum temperature of 38°C, and the responses were led off on the oscilloscope connecting with a RC coupled amplifier and a direct one, and the following results were obtained:1. An unfertil vitelline membrane was used as a contrast. The local responses of maximum height of 500μV with 200-250msec. of duration were generally observed, and occasionally after-potentials followed them. Plotting the maximum sizes of responses and the intensities of stimuli, the elevations increased exponentially in accordance with the growing stimuli. As for the polarities, the positive and the negative slow local responses were observed, when the polarities of shocks were reversed.2. Well developed primitive central nervous and circulatory systems were detected on the chick's neurula which was incubated under the suitable temperature for 40 hour, and with the changes in form of animal life, electric patterns of response were also transformed into very complicated shapes and many irregular impulses overlapped upon the after-potential.3. The primitive type of electrocardiogram was recorded from the preparations of 50 hour incubation, and it was nearly approximated to the typical pattern as labeled P-QRS-T, but QRS showed a dome in place of a spike.4. The response keeping all-or-none law was disclosed from the sample of 70 hour incubation, and the correlation between the latency and the stimulus draws hyperbola known as Weiss' formula, and the locus of this special pattern is deduced from the primitive cardiac muscle judging from the position of electrode.5. Briefly, the new born tissues like the primitive nervous and circulatory systems appear one after another upon a chick's neurula in the progress of development, and the varieties of oscillograms accompanied with the transformation of animal life were all clearly observed at the end of the local elevation.
Databáze: OpenAIRE
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