Scientific Reports of the Faculty of Agriculture, Okayama University
Published by the Faculty of Agriculture, Okayama University
ONLINE ISSN : 2186-7755

Studies on Aggressive Behavior in Mice

Kawamoto, Yasuo
Sato, Katsunori
Published Date
2003-02
Abstract
It is important to elucidate aggressive behavior for effective domestic animal management. Aggressiveness in mice, our model domestic animal, is partly caused by genetic factors. It has not, however, been studied in detail. The present study was designed to produce high and low aggression, inbreeding coefficient changes, and reproductive performance by selection. In addition, we investigated the effects of different population sizes on aggression, and also intracerebral dynamic neurotransmitters. Genetically different, high(H) and low(L) aggression mice were produces by selection. Our estimated values of heritability and realized heritability of aggression indicated that aggresiveness is influenced mainly by the environment. Inbreeding coefficients in H and L mice showed an increase of about 2% per generation, and 68.2 and 67.1% in the 34th generation of selection. Reproductive performance decreased slightly during selection, induced by the increase in inbreading coefficients. Isolated H mice induced the highest aggressiveness, without inducing aggressive behavior in isolated L mice. This result indicates that there is a genetic difference in the aggression control system between H and L mice. The serotonin turnover rate is reduced further in H mice than in L mice before the aggression test, suggesting that the serotonergic system is related to aggressive behavior. There were significant differences in dopamine levels between H and L mice. Results obtained from autoreceptor agonists indicate that H mice exhibit a high dopamine biosynthesis and release rate, while H and L mice differ in their aggression auto-control system through autoreceptors in the presynapse. H and L mice exhibit different aggressive behavior changes due to concentrations of dopamine D1 receptors.
Keywords
mice
aggressive behavior
selection
genetic parameter
neurotransmitter
ISSN
0474-0254
NCID
AN00033029