"Fear communication" via odor in inbred mice

Olfactory Cues and Sand Digging by Male Mice

Male Swiss-Webster mice ( N = 30) had access to a sand filled tube for 30 min. on 12 consecutive days. On Days 1 to 6 they dug sand that was clean, contained their own scent or was scented by other males. Ss dug significantly more scented (both own and other scented) than clean sand ( F = 6.31, p < 01) and dug the scented sand at significantly faster rates ( F = 4.05, p < .05). On Days 6—12 half the Ss in each group were switched to either clean or differently scented sand. No significant group differences were found although changes from scented to clean sand did depress the amount and rate of digging. Sand-digging studies have been used to test various motivational hypotheses, the present study illustrates the need for olfactory controls in such research and suggests the use of sand digging to study pheromones in mice.

Urine marking in male mice: responses to natural and synthetic chemosignals

The effects of natural chemosignals and their synthetic terpenic analogs on urinary marking in mice were investigated. The number and size of marking spots, and percentage of response and avoidance/counter-marking behavior, were measured for dominant and subordinate males. The males' marking behavior was found to differ significantly based on the type of stimulus sample used. Marking behavior in response to female urine was significantly altered by addition of synthetic analogs (farnesene isomers) to it. Both dominant and subordinate males avoided marking the section of the test area soiled with stimulus samples containing either natural or synthetic farnesenes. Differential responses of the dominant and subordinate male mice were observed.

Effects of water deprivation on urine marking and aggression in male house mice

This study assessed the effects of water deprivation on male mouse urine marking and aggressive behaviors and endurance. In Experiment 1, the size of marks and frequency of marking were examined in 3 groups given 3 different weights of potato/day as their source of water. Males receiving the least water, 1.5 g potato/day, marked at significantly lower rates than males receiving 3 g potato/day or 6 g potato/day (p less than 0.01). The size of urine marks of males was judged by a panel to be unaffected by water deprivation. In Experiment 2, water-deprived males were not as aggressive as normal males and when paired with them were almost always subordinated. Experiment 3 tested the hypothesis that water-deprived males lost fights simply because they were weaker than normal males. When water-deprived and normal males were tested to determine the maximum length of time they could swim, no differences were found (p greater than 0.05). We conclude that water deprivation can directly affect the urine marking and aggressive behaviors of male mice. Such changes may be of adaptive importance during times of drought.

Genetic analysis of active avoidance performance in mice

Mice of two inbred strains, C57BL/6J and DBA/2J, and the F1 hybrid of a cross between them were trained in an active avoidance jump-up task under distributed practice conditions. Significant differences in the performance of mice of the two strains were observed, with relatively poor performance by DBA/2J mice and relatively good performance by C57BL/6 mice. The performance of F1 hybrid mice did not differ significantly from DBA/2J mice. Crosses were made to produce segregating generations of mice. Their performance supported a single-locus model of inheritance for active avoidance jump-up behavior. Under these experimental conditions the dominant allelle (Aapd) was associated with poor performance while homozygosity for the recessive allele (Aapb) was associated with superior performance.

Social olfaction: a review of the role of olfaction in a variety of animal behaviors

Behavioral olfactory experiments were reviewed, relating the behavioral effects of pheromones to the psychophysical work in olfaction. Short descriptions of various experiments were used to show the importance of olfaction to the social behavior of animals by tracing the history of the experimental evidence and viewing the behavioral data pertaining to the discharge of pheromones and their effects and to look at the psychophysical evidence for olfactory acuity and the behavioral implications for the role of the physiological structures in olfaction.