Predatory aggression in lines of wild mice selected for interfemale aggression

Mice descending from lines previously selected for high and low levels of interfemale aggression and from a nonselected control line were exposed to live crickets on two consecutive test days. Latencies both to attack and to eat the cricket were recorded. No line or sex differences in attacking were found, although latency to attack decreased over test days. Control line mice were more likely to engage in the eating of the cricket than either the high or low selected lines, suggesting that the selection procedure may have dissociated attacking and eating components of predatory behavior.     

Effects of D- and L-amphetamine on the predatory behavior of Southern grasshopper mice,onychomys torridus

Adult male and female southern grasshopper mice (Onychomys torridus) were tested for predatory aggression toward cricket prey 1 hr after single injections of d-amphetamine (1 or 10 mg/kg) or 1-amphetamine (1 or 10 mg/kg). At the lower dose, d-amphetamine decreased feeding behaviors, while I-amphetamine altered attack-related behaviors. At the higher dose, both stereoisomers appeared to be equipotent in significantly decreasing 5 measures of predatory aggression. These results suggest that brain dopamine and norepinephrine play important roles in the regulation of predatory aggression of Onychomys torridus.     

Prey-dependent effects of fluprazine hydrochloride on predatory aggression in northern grasshopper mice (Onychomys leucogaster) and rats (Rattus norvegicus)

Treatment with the phenylpiperazine DU 27716 (fluprazine hydrochloride) inhibited the predatory killing of albino mice by northern grasshopper mice (Onychomys leucogaster) and of frogs by rats. This treatment had no effect on cricket predation by grasshopper mice or worm predation by rats. The prey-specific effect of fluprazine did not seem to result from a decreased tendency to attack nor was its effect restricted to prey showing characteristic rodent defensive responses. Rather, the drug seemed to increase fearfulness when the prey exhibited vigorous defensive behavior. It is possible that increased fearfulness induced by treatment with this drug may also contribute to its antioffensive effect during conspecific encounters.     

Effects of neonatal handling on play behavior and fear towards a predator odor in juvenile rats (Rattus norvegicus)

The effects of brief daily separation, also known as "handling," during the first 2 weeks of life on play behavior and fearfulness toward a predatory odor were assessed in juvenile rats. Handled rats were more playful than nonhandled control rats, and while handling had no effect on the direct response of these rats toward a predatory odor, handled rats did not exhibit a conditioned suppression of play when tested later in the same context where they had been exposed to the predatory odor. Handled rats were still wary of the environment in that they continued to show a heightened level of risk assessment behavior. These data suggest that early postnatal experiences may play a significant role in determining how an animal deals with predatory threats later in life.     

Effects of toxicosis on the predatory behavior of the golden hamster (Mesocricetus auratus)

The purpose of this study was to measure the effects that toxicosis had on the hamster's predatory behavior and to compare these results with those found in previous studies with grasshopper mice. A 0.15 M LiCl injection caused hamsters to develop a greater aversion and to inhibit their feeding and attack responses more frequently toward a house cricket than did a similar injection of NaCl. The added presence of an almond coating on the cricket prolonged the number of days that a hamster exhibited an aversion toward the prey and an inhibition to attack. Essentially, the inhibitory effects from toxicosis in the hamster paralleled those found with the grasshopper mouse. The differences in these inhibitory effects are attributed to inherent differences in the attack responses of the two rodents.     

Maternal behavior, paternal behavior, and pup survival in CD-1 albino mice (Mus musculus) in three different housing conditions

Parental behavior, food consumption, and pup development in litters of CD-1 albino mice (Mus musculus) with single mothers or paired mothers in 3 different housing conditions were compared. Fewer pups survived when parents were required to run in a wheel to obtain food, and these pups had lower weights than pups in the wheel-noncontingent and no-wheel groups. The presence of the male facilitated pup survival in the wheel-contingent group but had no effect on pup growth. Mice in the wheel-contingent group ran more revolutions than those in the wheel-noncontingent group and spent less time in parental care. In the wheel-contingent group, males spent more time running and ate less food than females, suggesting that males may indirectly facilitate pup development by providing food for the mother. The results suggest that the presence of the male increases pup care and may facilitate maternal behavior under appropriate environmental conditions.     

The role of the accessory and main olfactory systems in maternal behavior of the primiparous rat

The objective of this study was to analyze the respective roles of the main and accessory olfactory systems in the development of maternal behavior in the primiparous Wistar rat. Females underwent one of the following treatments: vomeronasal nerve section (VN), irrigation of nasal cavities with 5% ZnSO4 solution (ZN), surgical control, saline irrigation control, and normal control. Surgical or first irrigation were done before mating occurred. Irrigations were done every 7 days thereafter. The dams and their litters were observed from the day the litter was born (Day 1) through Day 16. Pup weights and temperatures were recorded daily. Home cages were checked daily for changes in nest location and number of times pups were found out of the nest. Retrieving tests were conducted on Days 4, 7, 10, and 13. The following behavioral items were observed: number of pup retrievals , number of times mother nosed or licked pups, percentage of litter returned to nest by end of test, dam self-grooming, dam climbing or rising, and dam digging or burrowing in shavings. The VN dams and their litters were not significantly different from the control dams and their litters on any of the measures taken. The ZN dams and their litters were not significantly different from their controls on all measures except for pup body temperature which was slightly lower from Day 13 through day 16 and pup body weight which was slightly lower from Day 12 through Day 16. Since these differences are very small, they do not seem to indicate a serious deficiency in maternal behavior. The results indicate that adequate maternal behavior develops with either of the two systems intact.     

绿色消费的许可效应：绿色让我们更不道德？

绿色消费属于道德范畴,消费者在助推绿色社会发展中的作用日益受到重视。然而,绿色消费会降低指定性道德约束或增强禁止性道德选择,消费者会变得不再绿色甚至自私(如享乐、撒谎或偷窃),这便是绿色消费的许可效应。从时间维度上来说,绿色消费许可效应的产生包括启动效应-绿色消费-许可效应三个阶段。有关该效应的理论解释是道德自我调节。从根本上来说,化解该效应需要消费者养成绿色生活方式,它包括两个路径：一方面,从绿色行为到绿色自我,抽象化表征行为,将绿色行为与自我概念相连接,采用自下而上加工方式实现;另一方面,从绿色自我到绿色行为,基于价值观-行为一致性原则,会促进个体产生更多绿色消费以及节俭和利他,采用的是自上而下加工。文章最后指出未来一些研究方向。     

The “prawn-in-the-tube” procedure in the cuttlefish: Habituation or passive avoidance learning?

This study examines whether or not habituation contributes to the regulation of the inhibition of predatory behavior observed during the "prawn-in-the-tube" training procedure. When presented with prawns that are visible behind glass but untouchable, cuttlefish promptly learn to inhibit their capture attempts. The first three experiments demonstrated that the acquired response in the course of training cannot be dishabituated. The fourth experiment demonstrated that the repeated application of a brief visual prawn stimulus, one that is terminated before the cuttlefish can strike, decreases attack latencies. Taken together, the results of this study establish that habituation does not play a significant role in this learning task. In fact, the present findings strengthen the results of previous studies suggesting that passive avoidance learning contributes to the regulation of the inhibition of predatory behavior.     

The organization of play fighting in the grasshopper mouse (Onychomys leucogaster): Mixing predatory and sociosexual targets and tactics

The body targets contacted, the type of contact made, and the patterns of defense and counterattack elicited by those attacks are examined in the play fighting of captive male and female pairs of grasshopper mice. The nape was the most frequently contacted body target, irrespective of the type of contact made, be it nosing, allogrooming, biting, or striking with a forepaw. The types of defense varied with both body area contacted and type of attack performed. Based on the topography and pattern of contact, it was concluded that grasshopper mice, as is the case for many other muroid rodents, primarily attack and defend targets otherwise contacted during precopulatory encounters. However, grasshopper mice, which are obligate carnivores, also attack and defend predatory targets, although less frequently than sociosexual targets. Surprisingly, predatory attacks were more likely to be counterattacked with predatory attacks, whereas sociosexual attacks were more likely to be counterattacked with sociosexual attacks. Conspecific aggression involves bites directed at the face, lower flanks, and dorsum. Neither the biting of these areas nor the tactics of attack and defense usually associated with such bites were observed during the juvenile interactions. There were no sex differences in either frequency or patterns of attack and defense in play fighting. The data presented for grasshopper mice shed light on the issue of mixing behavior patterns from multiple functional systems during play. Aggr. Behav. 26:319–334, 2000. © 2000 Wiley‐Liss, Inc.     

Food deprivation: Effects on the predatory behavior of southern grasshopper mice (Onychomys torridus)

The southern grasshopper mouse (Onychomys torridus) is a predatory and aggressive rodent native to the semi-arid scrub deserts of the southwestern United States and northern Mexico. Its natural diet consists primarily of arthropods and small vertebrates. In this study, we have evaluated the effects of food deprivation on the predatory behavior of adult male and female grasshopper mice to crickets (Acheta domesticus) and laboratory mice (Mus musculus). Subjects that were food-deprived for 48 hours spent more time eating dead but not living crickets than did controls that were provided free access to laboratory chow. There were no sex differences in the predatory behavior of grasshopper mice to living or dead crickets. Food deprivation also influenced the predatory behavior of grasshopper mice toward laboratory mice. With laboratory chow available ad lib, 6 of 43 (14%) male and 22 of 45 (49%) female grasshopper mice killed and ate laboratory mice within 48 hours of pairing. When deprived of food for 48 hours, 16 of 36 (44%) males and 15 of 19 (79%) females that did not kill in the previous experiment killed and ate laboratory mice. We concluded that food deprivation and type of prey are two variables which influence the frequency and intensity of predatory behaviors of grasshopper mice.     

Arousal and imitation of aggression

Forty boys, aged 5 and 6 years, viewed either an aggressive or nonaggressive film and were tested for imitation of the behavior displayed in the film. On the next day, before being tested again for imitation of the film, half the subjects in each film condition engaged in arousing play with the experimenter, and half in quiet play. According to the prediction, those aroused on the second day displayed more imitative behavior than those not aroused, regardless of which film they had seen. The results are discussed in terms of arousal as a performance variable in social learning.Thanks are due to Louis Morris, for advice and suggestions, and to Jeffrey Cohen, for assistance in data collection. This research was facilitated by funds from the Tulane University Council on Research.     

Effect of MAO A deficiency on different kinds of aggression and social investigation in mice

Monoamine oxidase A (MAO A) degrades serotonin, dopamine and noradrenaline, factors critically involved in the regulation of aggression. Different kinds of aggression were investigated in Tg8, a transgenic mouse strain lacking a functional MAO A gene. MAO A-deficient mice differ from wild-type C3H/HeJ (C3H) in terms of showing higher territorial, predatory and isolation-induced aggression. Tg8 demonstrated shorter latencies to cricket killing and to the first attack after 6 weeks isolation than C3H mice. In the resident-intruder paradigm, MAO A-lacking mice were more aggressive than C3H when tested as intruders. In contrast to C3H, attack in Tg8 mice did not depend on different aggressiveness of intruders of BALB/c, A/Sn and C3H strains. Tg8 mice displayed no increase in aggression but demonstrated reduced social investigation towards anesthetized, as well as towards juvenile BALB/c males. Thus, MAO A deficiency in Tg8 mice is accompanied by increased expression of different kinds of aggression, as well as by disruption of normal pattern of social interaction.     

Intermale fighting and predatory behavior in house mice: An analysis of behavioral content

Two forms of aggression, intermale and predatory, wwere compared on the basis of behavioral content. Male wild mice were presented with opponents of two types, nonaggressive male mice and crickets, and the amounts of time spent in each of 18 behaviors were recorded. Results from analyses of variance and principal components analyses indicated that the structure of behavioral content differs greatly for intermale fighting and predatory behavior. It was, therefore, concluded that the integrated patterns of beahvior were controlled by separate mechanisms for predatory versus intermale aggression.     

Serotonin's influence on predatory behavior of highly aggressive cba and weakly aggressive DD strains of mice

The effects of serotonin were studied on locust-killing behavior of mice from low (DD) and high (CBA) predatory aggressive strains. 5-HTP injected intraperitoneally (50 and 100 mg/kg) or 5-HT administered into the lateral ventricle (10 μg) significantly reduced locust-killing behavior in highly aggressive CBA mice. Imipramine (20, 30, and 40 mg/kg) elicited a dose-dependent inhibitory effect on predatory behavior. Fluoxetine (10 and 20 mg/kg) alone had a slight influence on locust-killing behavior but potentiated the action of the subthreshold dose of 5-HTP (25 mg/kg). Pretreatment with the blocker of 5-HT₂ type receptors methysergide (2 mg/kg) abolished the inhibitory effect of 5-HTP. These finding indicate that serotonin of the brain exerts an inhibitory effect on predatory behavior in mice. In contrast, neither lesion of the dorsal raphe nucleus (although significantly depleting the brain serotonin) nor treatment with methysergide (2 mg/kg) induced locust-killing behavior in weakly aggressive DD mice. Low predatory aggressiveness in DD mice is suggested to be related to the low tonus of the mechanisms activating killing behavior rather than to excessive serotonergic inhibitory influences.     

Event-related potentials, reaction time, and response selection of skilled and less-skilled cricket batsmen

The differences in P300 latency, P300 amplitude, response selection, and reaction time between skilled and less-skilled cricket batsmen have been investigated. Eight skilled and ten less-skilled right-handed batsmen each viewed 100 in-swing, 100 out-swing, and 40 slower deliveries displayed in random sequence from projected video footage whilst their responses and electroencephalograms were recorded. Logistic regression was used to derive a discriminative function for the P300 data. This was done to determine whether the skilled batsmen differed from the less-skilled batsmen on the basis of pooled P300 amplitude and latency data. All the batsmen were correctly characterised as being skilled or less-skilled. Logistic regression equations with reaction time and correctness of response data indicated that behavioural data do not correctly classify skilled performance. It is suggested that skilled cricket batsmen have a superior perceptual decision-making ability compared with less-skilled cricket batsmen, as measured by P300 latency and amplitude. This appears to be the first study showing a link between skill and cerebral cortical activity during a perceptual cricket batting task and it could pave the way for future studies on mental processing in cricket batsmen.     

Various relationships between predatory dominance and aggressive behavior in Pairs of cats

The experiments were performed on adult male cats selected initially as good mousekillers. Cats were tested in pairs and each pair was introduced separately to the experimental compartment. The attitude toward the partner before and during the predatory competition test as well as superiority in catching and killing the mice, considered as an index of dominance, were registered. In the course of experiment five types of relations between the predatory dominance and aggressive behavior were observed. The concept of dominance as an outcome of several factors was discussed. It was concluded that predatory dominance is not based exclusively on aggressive mechanisms, as it may be formed and sustained without overt aggression.     

Predatory aggression: Midbrain-pontine junction rather than hypothalamus as the critical structure?

Electrical stimulation of sites in the region of the ventromedial periaqueductal gray substance at the level of the midbrain–pontine junction was found to elicit a predatory attack by a cat upon a rat. The intensity of stimulation required to elicit the attack was three to four times less than that required to elicit similar behavior by hypothalamic stimulation. The results suggest that anatomically distinct regions of the periaqueductal gray substance are concerned with the regulation of predatory and affective forms of aggressive behavior. The difficulty in reconciling these results with the preeminent role assigned the hypothalamus in the organization of predatory behavior is also discussed.     

"Instant success": turning temptations into cues for goal-directed behavior

Contrary to lay intuition, counteractive control theory posits that tempting food cues can help individuals to act in accordance with their long-term dieting goal. However, studies have shown that temptations trigger goal-directed behavior only in successful but not in unsuccessful self-regulators. The aim of the present study was to test whether it is possible to create facilitated temptation-goal associations in unsuccessful dieters using implementation intentions (e.g., "If I see or smell chocolate then I will follow my goal to diet") and whether this indeed stimulates more successful self-regulation. It was found that implementation intentions linking a temptation to a dieting goal lead to self-perceived improved resistance to (Study 1) as well as reduced consumption (Study 2) of tempting snacks compared to a control condition. Moreover, Study 2 revealed that the reduced snack consumption was indeed related to facilitated temptation-goal associations in participants who had formed implementation intentions.     

Analysis of the catnip reaction: mediation by olfactory system, not vomeronasal organ

Pet owners and behavioral scientists alike are fascinated by unique behavioral reactions that cats show in the presence of catnip. These experiments explored the possibility that the catnip reaction might be triggered by chemosensory stimulation of the vomeronasal organ. In the chewing and mouthing of the catnip source, substances might be dissolved in saliva and transported to the vomeronasal organ. The rolling and rubbing during a catnip reaction might be a sexual response activated by the accessory olfactory system since the system projects to parts of the brain involved in mediation of sexual behavior. However, removal of the vomeronasal organ did not attenuate any of the behavioral reactions to catnip. Olfactory bulbectomy immediately eliminated catnip responding, revealing that the chemosensory stimulus evoking the catnip reaction is undoubtedly mediated through the main olfactory system. Catnip activates behavioral elements associated with several species-specific behaviors, including sniffing and chewing as associated with oral appetitive behavior, rolling and rubbing characteristic of female sexual behavior, batting the catnip source characteristic of play behavior, and a type of kicking associated with predatory behavior. These behavioral reactions occur randomly and intermittently.