Chronogenetics : the inheritance of biological time / by Luigi Gedda and Gianni Brenci.

  • Gedda, Luigi.
Date:
[1978], ©1978
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Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Chronogenetics : the inheritance of biological time / by Luigi Gedda and Gianni Brenci. Source: Wellcome Collection.

    25/240 (page 9)
    The Scientific Study of Time 9 New points of departure for the study of memory start from the consideration that the nervous pathways conveying sensations to body centers are highly specialized. Other hypotheses hold that each afferent fiber is capable of producing a synthesis of specific substances determining both the sensation and the trace of the memory acquired. Ungar, Clark and Galvan^ performed an experiment which aroused a fear of darkness in rats which usually are not afraid of this state but rather like it. The authors achieved this effect, which they call scotophobia, by putting the experimental rats into darkened metallic cages and subjecting them to electric shock. They then removed the brains of the ani¬ mals thus frightened and isolated an active substance, a peptide that they called scotophobine and succeeded in producing syn¬ thetically. When scotophobine is injected into other rats, and similarly into goldfish, it produces a fear of darkness which lasts for three or four days. Ungar and his associates have also extracted a substance pro¬ duced from rats' brains when they undergo prolonged acoustical stimuli and become used to them. In addition, Ungar as well as Domagk and Zippel,^ have succeeded in imparting a preference for one color and an aversion for another to untreated goldfish by means of transferring substances from treated goldfish. These authors suggest that a comparison between the chemical struc¬ tures of these substances of opposing action could be very in¬ structive. The existence of a macromolecular biochemical memory com¬ pound is the most probable hypothesis to explain these activities, difficult as it may be to distinguish the product of physicochemi- cal activation of nerve fibers from that of specific proteins of the synaptic surfaces. As far as the duration which a recollection may be preserved is concerned, a phenomenon of transfer onto ribonucleic acid (RNA) could be postulated for short memory, whereas in the case of long memory, either the transfer and/or the translation into a specific polypeptide which is then preserved might be necessary. Evocability or recall, at a greater or lesser 2. Ungar, G., Clark, R. H., and Galvan, L.: In Nature, 2/7:1259, 1968. 3. Domagk, G. F., and Zippel, H. P.: In Experientia, 25:938, 1969.