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Abstract— An acidic protein has been isolated from the optic lobes of two cephalopods, Sepia officinalis and Loligo vulgaris. The protein has been obtained in pure form by fractionation with ammonium sulphate and chromatography on DEAE‐cellulose and Sephadex G 100. Its apparent molecular weight is 13,000–15,000. Glutamic and aspartic acids account for 35 per cent of the amino acid residues. The protein binds Ca2+ ions with an apparent dissociation constant of 2·5 × 10−5 M at physiological concentrations of KCI. Antibodies have been prepared against the protein purified from Sepia officinalis. By the micro‐complement fixation technique it has been shown that the protein is highly concentrated in the nervous system of cephalopods and that the amount in the axoplasm of squid giant axons is eight to nine‐fold higher than in the optic lobes of the same animal.

The carrier-mediated transport of GABA in rat brain synaptosomes was strongly and permanently inhibited byL-2,4-diaminobutyric acid (DAB). In order to discriminate between carrier-mediated and non-carrier-mediated release of [(3)H]GABA, synaptosomes prelabeled with 0.5 μM [(3)H]GABA in the presence of 100 μM DAB, or with 0.2 μM [(3)H]GABA without DAB, were superfused in conditions stimulating the release of [(3)H]GABA. Only the release elicited by unlabeled GABA or DAB (by homo- and heteroexchange, respectively) was strongly inhibited in DAB-pretreated synaptosomes. The spontaneous release and the release induced by 56 mM KCl in the presence of CaCl2, by the ionophore A23187, by ouabain, by lack of K(+), or by purified black widow spider toxin were unaffected or only barely decreased in DAB-treated synaptosomes, and therefore do not seem to be mediated by the DAB-blocked GABA carrier.

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From Piaget's research down to the most recent work of Carey andWellman; it has been attempted to describe the development of basic concepts such as living and animal in the child. There have been less frequent attempts to draw from the resultsof these investigations suitable teachings for correctscientificeducation at school. The educationalsystem continues to make proposals which clash clearly with the indications of research.The aim of our research is to bridge the gap between these two needs, as well as to study the development of the concept of living and animal in seven to twelve-year-olds and to draw the necessary educational conclusions. In particular, we have investigated how these concepts are modified at the various ages, between boys and girls and between country dwellers, who have a direct experience of animals, and town dwellers, who do not. The results are on the one hand in agreement with those of international research, adding information concerning the variables sex and direct experience, hitherto relatively uninvestigated; on the other, th.ey provide d~nite indications as to the succession of contents to offer in a science syllabus, to the advisability of taking into account the considerable differencebetween boys and girls, and to the need to enhance the role of practical experience of exploring and laboratory work in studying natural science.