Influence of colony lighting conditions on home-cage spontaneous aggression.

Abstract

In a series of experiments the effects of colony lighting conditions on homecage aggression were examined, and the relation among measures of homecage aggressive behavior and shock-induced aggression were determined. In each experiment rats were maintained under either a light/dark (LD) cycle or a continuous light (LL) schedule. Experiments IA and IB indicated that for cages of LD rats the highest rates of home-cage aggression occurred during the dark segment of the light cycle whereas the lowest rates of aggression characterized the light segment. In contrast, the rate of home-cage aggression was low and constant across time periods for cages of LL rats. Reflecting these differences between lighting conditions, regression analyses in Experiment IB identified a periodic trend following the fundamental sine curve in the home-cage aggression data from cages of LD rats but not in the data from cages of LL rats. In Experiment 2 the relation between individual differences in home-cage aggression and shock-induced aggression was found to be time dependent for pairs of LD rats. Correlations based on scores of home-cage aggression and shock-induced aggression obtained during the dark segment were positive and statistically significant. Correlations of these two aggressive behaviors based on scores obtained during the light segment were not statistically significant. For pairs of LL rats, no timedependent pattern in the relation of home-cage aggression to shock-induced aggression was observed.The lighting conditions under which laboratory animals are maintained can have significant influences on a range of biologically important behaviors (e.g., Richter, 1965;Wurtman, Axelrod, & Kelly, 1968;Zucker, 1971). In a recent series of experiments Knutson, Hynan, and Kane (1976) demonstrated that shock-induced aggression was also influenced by the colony lighting conditions under which male rats were raised. These experiments indicated that rats maintained on a 12:12 hr light/dark (LD) cycle

Effect of Environmental Lighting on Aggressive and Anxious Behavior in Male Mice

“…The highest performance in aggression coincides w i t h that i n s p o n t a n e o u s behavior i n mice. T h e spontaneous aggression of rats in the LL cycle showed lower than that in the LD cycle (Kane and Knutson, 1976). Taken together, it was hypothesized that the DD group showed the highest aggression and the LL group showed the lowest aggression.…”

“…On a continuous light schedule, the muricidal behavior increased i n male rats (Giammanco et al, 1990). On the contrary, the rate of aggression was higher in the light-dark cycle environment than that in the continuous light environment in rats (Kane and Knutson, 1976). In mice, few reports were available for t h e relation between environmental lighting and aggressive behavior.…”

The effect of time of test on muricide, irritability, and open-field activity in the rat

“…The most serious flaw was that testing was performed at only one time during either the dark or the light portion of the cycle. The studies by Kane and Knutson (1976) and Knutson et al (1976) very clearly demonstrated the cyclical nature of spontaneous aggression and shock-induced fighting, respectively. Both measures revealed peaks later into the dark cycle than the point at which testing was performed by Thome and Hutton.…”

“…In addition, a periodic trend in fighting was noted in the light-dark animals, with a peak in the dark portion of the cycle. Kane and Knutson (1976) studied spontaneous home-cage fighting in rats as a function of lighting conditions and found that the highest rates occurred during the dark segment of the cycle. The rate of fighting was low and relatively constant in rats maintained under constant light.…”

A computer program that produces line graphs

“…Black·and-white prints can be made from the microfilm. Such prints were used in the Kane and Knutson (1976) Limitations. The plotting program uses primarily lower level plotting subroutines that draw lines, character strings, and plotting symbols.…”