Biomedical subjects

E D Kemble

Publications and source records attributed to E D Kemble.

At least 19 recordsLinked to original sources

PubMed1997

Immediate and long-term effects of novel odors on risk assessment in mice.

The effects novel predator and nonpredator odors on risk assessment and nonagonistic behaviors were investigated in a series of 4 experiments. During initial exposure, a synthetic predator odor proved to be no more effective than sheeps' wool in evoking defensive behaviors among either naive or previously defeated mice. When the mice were tested following 60-min habituation to the odors, the predator odor consistently elicited stronger defensiveness than sheeps' wool. Substitution of a pungent nonpredator odor (citronella) for that of sheeps' wool in Experiment 4 however, elevated levels of risk assessment among habituated mice to those evoked by the predator stimulus. The use of prior habituation trials seems to provide a sensitive procedure for assessing differential responsiveness to odors and should be useful for anxiogenic, but not anxiolytic, experimental manipulations. The data further suggest that odor novelty and intensity are important contributors to heightened levels of antipredator defense.

Animals↗

PubMed1993

Differential effects of prior dominance or subordination experience on conspecific odor preferences in mice.

Preferences for the soiled bedding odors of familiar and unfamiliar conspecifics were assessed among male mice rendered dominant or subordinate by a series of resident-intruder encounters. Alpha males preferred the odors of their familiar antagonist most strongly. Subordinates, in contrast, showed strongest preferences for unfamiliar females and a weaker preference for alpha odors. When female odors were eliminated from the preference test, alphas continued to show the strongest preference for familiar subordinate odors while subordinates displayed roughly equivalent preference for the odors of familiar alphas and unfamiliar males. It is suggested that the apparent mild preferences of subordinates for dominant conspecific odors reflects fear motivated risk assessment. In contrast, approaches of dominants to subordinate odors seems to be appetitively motivated. Generally recognizable subordination odors may be useful to unfamiliar males in recognizing exploitable resources.

Aggression↗

PubMed1992

Effects of eltoprazine hydrochloride on reactivity to conspecific or novel odors and activity.

Treatment with eltoprazine (DU 28853) increased the number of entries by male mice into compartments containing the odors of male and female conspecifics. This effect was most pronounced when odors were provided by previously defeated males. In contrast, the drug had no effect upon responsiveness to the odors of cinnamon and chocolate. The results suggest that eltoprazine may selectively increase reactivity to conspecific odors and that this effect is further enhanced by agonistic experience. Eltoprazine also substantially increased activity levels in all experiments. Since hyperactivity occurred both in the presence and absence of conspecific odors, however, the drug's effects on activity and olfaction seem to be largely independent. The results suggest that the aggression-modulating effects of eltoprazine, as well as other drugs, may be mediated in part by their effects on normal olfactory function.

Aggression↗

PubMed1992

Test-specific effects of FG-7142 on isolation-induced aggression in mice.

Treatment with FG-7142 decreased isolation-induced attack, but not defense, by male mice when the residents' home cages contained only a sawdust substrate. When a small wooden nesting box was added to the cage (Experiment 2), however, FG-7142 somewhat increased levels of attack. Time spent in the nesting box was also increased, while overall levels of social interaction were decreased, by drug treatment in Experiment 2. The latter findings are consistent with FG-7142's well-documented anxiogenic properties and indicate that this drug is probably proaggressive in its actions. The antiaggressive effects of FG-7142 in Experiment 1 may have resulted from drug-induced fear behaviors that were incompatible with attack. Alternatively, Experiment 2 suggests the possibility that species-typical attack may be defensively motivated under some circumstances. Although the antiagressive properties of eltoprazine and yohimbine were unaffected by the addition of the nest box (Experiment 3), the provision of some sort of refuge within the testing apparatus may be an important methodological consideration for studies employing resident-intruder paradigms.

Aggression↗

PubMed1991

Effects of yohimbine on isolation-induced aggression, social attraction, and conspecific odor preference in mice.

Yohimbine treatment inhibited isolation-induced attack in mice but had no effect on defense. The drug also increased social distances and produced a transient decrease in preference for conspecific male odors. The antiaggressive actions of yohimbine parallel those reported for the anxiogenic beta-carbolines and for phenylpiperazine "serenic" agents. The results emphasize the importance of supplementing conspecific agonistic encounters with additional behavioral measures such as nonagonistic social attraction in evaluating antiaggressive drugs. The decreased responsiveness to conspecific odors seen in Experiment 3 also suggests that increased conspecific avoidance may be mediated, in part at least, by altered olfactory processes.

Aggression↗

PubMed1991

Effects of eltoprazine hydrochloride on exploratory behavior and social attraction in mice.

The effects of eltoprazine (DU 28853) on exploratory behavior and conspecific social attraction were examined in four experiments. Drug treatments somewhat enhanced three forms of exploratory behavior but decreased social attraction. The results indicate that eltoprazine, in sharp contrast to fluprazine, weakly ameliorates neophobic responses. Both eltoprazine and fluprazine seem to increase the aversiveness of encounters with other organisms, however. The latter effects may be mediated, in part at least, by some alteration in olfactory function.

Aggression↗

PubMed1990

Effects of regional amygdaloid lesions on flight and defensive behaviors of wild black rats (Rattus rattus).

Flight and defensive behaviors of wild black rats (R. rattus) in response to nonpainful threatening stimuli were examined before and after regional amygdaloid lesions. Striking disruption of flight was found following damage to all major amygdaloid regions. In contrast, reduced defensiveness was most consistently associated with damage to cortical and, perhaps, central nuclei. The diffuse organization of flight behavior may result from extensive modality-specific cortical afferents to the amygdala and the varied provided by naturalistics threats. The more restricted representation of defensive attack may have resulted from diminished responsiveness to vibrissal stimulation mediated by medial and dorsomedial amygdaloid structures.

Agonistic Behavior↗

PubMed1986

Effects of fluprazine hydrochloride on conspecific odor preferences in rats.

The effect of Fluprazine Hydrochloride (DU 27716) on preference for conspecific male, estrous female and food odors was examined in male rats utilizing a two-compartment choice apparatus. Treatment with 8.0 mg/kg Fluprazine enhanced the preference of males for male odors but had no effect on preference for either estrous female or food odors. The drug-induced enhancement of male odor preference is consistent with the suggestion that Fluprazine interferes in some way with the processing of olfactory stimuli which normally precede offensive attack. The failure of the drug to alter the preference of males for estrous female odors suggests that the increased sniffing of estrous females noted during social testing may be secondary to other sources of conspecific stimulation or may reflect a highly transitory effect on olfactory processes. These results suggest that the suppressive effects of Fluprazine on intermale aggression and copulation are mediated by somewhat distinct mechanisms.

Animals↗

PubMed1986

Effects of food deprivation on caffeine consumption in male and female rats.

The effect of food deprivation on caffeine consumption was investigated in male and female rats utilizing two-bottle preference tests. During ad lib food and water access, proportional consumption of six increasingly concentrated caffeine solutions (0.01-0.125%) steadily declined as concentration increased with no sex differences. Across concentrations, females tended to ingest more mg/kg caffeine than males. Food deprivation increased both proportional and mg/kg caffeine consumption in both sexes. When returned to ad lib food, proportional, but not mg/kg, caffeine consumption returned to pre-deprivation levels. Consumption of a quinine solution (0.02%), comparable to the caffeine in two-bottle preference, declined somewhat during food deprivation. These results indicate that caffeine preference and mg/kg consumption are increased by food deprivation and that this effect does not result from increased preference for bitter tastes per se. Rather, the results suggest that increased caffeine intake during food deprivation is due to a specific interaction between reduced body weight and the drug. The results also suggest that the deprivation effect is somewhat weaker in females than males, perhaps due to sex differences in reactivity to caffeine.

Analysis of Variance↗

PubMed1986

Effects of septal-forebrain lesions on maternal aggression and maternal care.

Septal-forebrain lesions significantly increased the defensive reactions of lactating Long-Evans rats (n = 13) relative to nonlesioned control females. The lesions greatly enhanced defensive behaviors on a number of standard tests (e.g., responsiveness to humans and anesthetized conspecifics) while abolishing aggression toward intruding male conspecifics. The lesions also produced a striking disruption in maternal behavior as evidenced by absence of nest building, reduced litter weights, failure to retrieve, lick, or nurse pups, and increased cannibalization. While these results cannot be interpreted as indicating that maternal aggression is equivalent to offense, they are congruent with such a view. Certainly they are not supportive of a view that maternal aggression is primarily defensive. The lesion-induced abolition of maternal attack may have resulted from an inhibition of offensive tendencies by heightened defensiveness and/or reduced pup stimulation. There was no evidence that the lesion-induced impairment in maternal behavior resulted from a failure to sequence the individual behavioral acts comprising maternal behavior. Rather, all features of maternal care seemed to be greatly attenuated.

Aggression↗

PubMed1985

Mouse killing, insect predation, and conspecific attack by rats with differing prior aggressive experience.

Mouse-killing, cockroach predation, and conspecific attack were examined in male Long-Evans rats with a history of intraspecific aggression (n = 20), defeat (n = 20), or no aggressive experience (n = 20). Roaches were more likely to be attacked during 30 min tests, and were attacked more rapidly than mice or rats regardless of previous social experience of subjects. Rats with aggressive experience attacked conspecifics more readily than subjects with defeat or no experience. There was no effect of prior experience on mouse-killing. These results indicate that mouse-killing does not correspond closely to either predation or intraspecific attack.

Aggression↗

PubMed1985

Fluprazine hydrochloride does not decrease defensive behaviors of wild and septal syndrome rats.

Recent studies indicate that fluprazine hydrochloride reduces offensive attack in laboratory rats and mice without decreasing defensive behavior during conspecific encounters. Since wild rats and rats displaying the "septal lesion syndrome" show much more pronounced defensive reactions than do normal laboratory rats, these animals were used to provide a more critical test of fluprazine's effectiveness on defense. When a dose of fluprazine hydrochloride (8 mg/kg), previously shown to be highly effective in reducing or eliminating offense, was given to wild and septal syndrome rats these animals showed no reliable decrement in a wide range of defensive reactions including biting attack (defensive attack) to human handling and other stimulation. These findings support the view that fluprazine does not appreciably affect defensive attack or other defensive behaviors even though it strongly inhibits offensive attack.

Aggression↗

PubMed1984

Taming in wild rats following medial amygdaloid lesions.

Flight behavior, startle reactions, and defensiveness to nonpainful stimuli were examined before and after medial amygdaloid lesions in wild Rattus norvegicus and R. rattus. Lesions which included bilateral damage to the medial nucleus strongly reduced defensiveness but had no effect on flight behavior. In contrast, damage to nearby medial structures, which spared the medial nucleus, had no effect on defensiveness but reduced flight behavior. All lesions produced a transient decrease in activity but had no effect on startle reactions. The results suggest a differential organization of flight and defense behavior within the medial amygdala.

Amygdala↗

PubMed1984

Sex differences in shock motivated behaviors, activity, and discrimination learning of northern grasshopper mice (Onychomys leucogaster).

Sex differences in the behavior of the highly predatory northern grasshopper mouse (Onychomys leucogaster) were investigated in a series of eight experiments. Female mice acquired two-way avoidance behavior more slowly, but passive avoidance more rapidly, than males. Females also buried a shock probe more completely than males and showed more escape behavior during open field testing. There were no sex differences in flinch-jump thresholds or escape from electric shock, general activity levels, or acquisition and reversal of a position discrimination. It is suggested that the sex differences in aversively motivated behavior result from an increased tendency of females to respond defensively to focal sources of aversive stimuli. The enhanced defensiveness of females may be an adaptation to higher levels of pup predation resulting from the large territories required by their predatory specialization and their association with other, more abundant, rodent species.

Animals↗

PubMed1979