Comparative Analysis of the Behavioral and Biomolecular Parameters of Four Mouse Strains

Abstract

The use of mice as experimental models in pharmacological and biochemical research began over 100 years ago, during which time different mice strains with specific features were developed. Numerous studies demonstrate that the pharmacological efficacy of various compounds significantly varies among different animal strains, a factor which must be considered when analyzing experimental data. The Sabra strain, developed more than 35 years ago, is widely used for research in Israel but has an unclear origin and is not characterized as well as other strains. Comparative analyses of the molecular characteristics of Sabra and other strains should help to understand their characteristics and to enhance the validity of their experimental use. Thus, four mouse strains-outbred ICR and Sabra as well as inbred C57Bl/6J and Balb/c were compared. Animals' weight, blood corticosterone and hippocampal BDNF mRNA levels were measured, and animals' behavior was compared using the EPM, open field, FST, and hot plate tests. We found that although Sabra mice are bigger and heavier than other tested lines, this is not reflected in behavior or in biomolecular features, wherein Sabra mice lay within the diapason of other tested animals. Thus, behavioral tests of anxiety-like behavior and locomotor activity revealed that Sabra mice scored close to the mean of all tested lines. Analysis of blood corticosterone levels did not show significant differences among tested strains. We also found a correlation between general and locomotor activity of the tested strains and their hippocampal BDNF mRNA expression. In summary, we may conclude that Sabra mice have traits similar to the better known lines, and therefore they are good subjects for neuroscience research.

Loss of the mu opioid receptor on different genetic backgrounds leads to increased bromodeoxyuridine labeling in the dentate gyrus only after repeated injection

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