Chemical and Anatomical Plasticity of Brain

Abstract

relative mobilities and the numbers of the different carriers. 7. The usual test of the quality of a crystal is its residual resistance ratio, that is, the ratio of the resistivity at room temperature to the resistivity at 4.2?K. Although at present there is no way to relate the resistance ratio and purity of one metal to the resistance ratio and purity of another, the ratio is a reliable test between different samples of the same metal. The resistance ratios of the best samples currently available of some of the metals discussed here are, Cu, 8000; Zn, 60,000; Sn, 100,000; Fe, 300; Ni, 2700; Mo, 4000; W, 80,000. 8. Yu. Gaidukov, Soy. Phys. JETP (English Transl.) 10, 913 (1960); J. R. Klauder and relative mobilities and the numbers of the different carriers. 7. The usual test of the quality of a crystal is its residual resistance ratio, that is, the ratio of the resistivity at room temperature to the resistivity at 4.2?K. Although at present there is no way to relate the resistance ratio and purity of one metal to the resistance ratio and purity of another, the ratio is a reliable test between different samples of the same metal. The resistance ratios of the best samples currently available of some of the metals discussed here are, Cu, 8000; Zn, 60,000; Sn, 100,000; Fe, 300; Ni, 2700; Mo, 4000; W, 80,000. 8. Yu. Gaidukov, Soy. Phys. JETP (English Transl.) 10, 913 (1960); J. R. Klauder and J. E. Kunzler, The Fermi Surface, W. A. Harrison and M. B. Webb, Eds. (Wiley, New York, 1960), p. 125. 9. A. B. Pippard, Phil. Trans. Roy. Soc. London A250, 325 (1957). 10. A description of these experimental techniques for determining the shape of the Fermi surface is given by A. B. Pippard, Rept. Progr. Phys. 23, 176 (1960); their application to copper is given in several papers in The Fermi Surface, W. A. Harrison and M. B. Webb, Eds. (Wiley, New York, 1960). 11. For studies of tin, see N. E. Alekeseevskii, Yu. P. Gaidukov, I. M. Lifshitz, V. G. Peschanskii, Sov. Phys. JETP (English Transl.) 12, 837 (1961); for studies of lead, see N. E. J. E. Kunzler, The Fermi Surface, W. A. Harrison and M. B. Webb, Eds. (Wiley, New York, 1960), p. 125. 9. A. B. Pippard, Phil. Trans. Roy. Soc. London A250, 325 (1957). 10. A description of these experimental techniques for determining the shape of the Fermi surface is given by A. B. Pippard, Rept. Progr. Phys. 23, 176 (1960); their application to copper is given in several papers in The Fermi Surface, W. A. Harrison and M. B. Webb, Eds. (Wiley, New York, 1960). 11. For studies of tin, see N. E. Alekeseevskii, Yu. P. Gaidukov, I. M. Lifshitz, V. G. Peschanskii, Sov. Phys. JETP (English Transl.) 12, 837 (1961); for studies of lead, see N. E.

Visual experience and age affect synaptic organization in the mushroom bodies of the desert ant Cataglyphis fortis

“…The visual and odor evoked structural modifications in the Drosophila brain are restricted to a critical period of the first days of adult life, whereas in Cataglyphis fortis the structural changes in the MBs are not limited to an early stage. It is also in vertebrates that artificial manipulation of the environment could induce neurochemical and neuroanatomical plasticity in the adult brain (Bennett et al, 1964;Floeter and Greenough, 1979;Tieman and Hirsch, 1982).…”

Relative Medial and Dorsal Cortex Volume in Relation to Sex Differences in Spatial Ecology of a Snake Population

“…Although it is plausible that sex differences in MC volume are already present from early stages in development, many proximate mechanisms associated with learning and memory might also explain correlations between functional demands and neural volume. Functional and morphological plasticity within the brain are often correlated with learning or experience [e.g., Bennett et al, 1964;Polley et al, 2004]. Within the hippocampus, learning might induce neurogenesis [Gould et al, 1999a;Shors et al, 2001], enhance neuron survival [Leuner et al, 2004], and increase dendritic spine density [Moser et al, 1994;O'Malley et al, 2000;Leuner et al, 2003].…”

Environmental enrichment, sexual dimorphism, and brain size in sticklebacks

“…There is also evidence to suggest that various animals are capable of increasing their brain size in response to environmental enrichment (Bennett, Diamond, Krech, & Rosenzweig, 1964; Bennett, Krech, & Rosenzweig, 1964; Bennett, Rosenzweig, & Diamond, 1969; Cummins, Walsh, Budtz‐Olsen, Konstantinos, & Horsfall, 1973; Riege, 1971; Scotto Lomassese et al., 2000; Technau, 1984). However, the evidence for this effect from fish studies is conflicting.…”