Aggressive Behavior In Rats Research Articles

On the generalizability of shock-elicited aggressive behavior in rats

The aggressive behavior of rats was observed both in a colony situation and in a shock-elicited aggression situation. Several aggressive behaviors seen in the colony were not observed during footshock. Shoving and upright boxing were observed in both situations, although several components of these behaviors were missing during footshock. These data suggest that behavior elicited by footshock may be “displacement” activity rather than aggressive or defensive behavior.

Effects of lesions of the locus coeruleus on aggressive behavior in rats

Bilateral lesions of the nucleus locus coeruleus increased shock-induced fighting behavior and apomorphine-induced aggression in rats. On the other hand, these lesions failed either to change mouse-killing behavior in isolated rats or to induce this behavioral pattern in natural non-killers.

CANNABIS, CATECHOLAMINES, RAPID EYE MOVEMENT SLEEP AND AGGRESSIVE BEHAVIOUR

1. Previous work from our laboratory has shown that cannabis induces aggressive behaviour in rats that have been deprived of rapid eye movement (REM) sleep. It was suggested that this effect was related to brain catecholamines, with dopamine playing an agonist role and noradrenaline an inhibitory one. The present paper describes new experiments dealing with this subject. 2. Previous REM sleep-deprivation enhanced both delta9-tetrahydrocannabinol (THC)-induced hypothermia and nomifensine effects on aggressive behaviour. 3. A marihuana extract decreased brain dopamine turnover in REM sleep-deprived rats, an effect not observed in non-deprived rats. Noradrenaline metabolism was not altered. 4. Fighting behaviour was elicited in REM sleep-deprived rats treated with 4 different dopamine-beta-hydroxylase inhibitors. 5. Apomorphine, nomifensine and delta9-THC administered to non-deprived rats pretreated with bis(4-methyl-1-homopiperanzinyl-thiocarbonyl) disulphide (Fla-63), induced fighting behaviour. 6. Nomifensine and apomorphine induced fighting in non-deprived rats pretreated with delta9-THC. 7. Clonidine inhibited the fighting elicited in REM sleep-deprived rats by either delta9-THC or Fla-63 pretreatment. 8. The data are discussed in terms of the influence of REM sleep-deprivation (or the stress associated with deprivation) on the response to dopaminergic drugs and cannabis. Taken together they emphasize the participation of brain dopamine and noradrenaline systems in the aggressive behaviour studied.

The ventromedial hypothalamus and aggressive behaviour in rats

Male rats were given bilateral lesions in either the anterior or posterior ventromedial hypothalamus (VMH). The intermale aggressive behaviour of these animals within their own territory was observed before and after the surgical procedure and compared with the behaviour of sham-operated animals. The effects of anterior VMH lesions include an increased tendency to respond with frontal threatening upon approach of a conspecific male. This behaviour closely resembles the aggressive responses described in “shock-induced aggression” tests. Posterior VMH lesions facilitate territorial aggressive behaviour characterized by approaching the opponent followed by lateral threatening and fighting. It is suggested that 2 distinct neural substrates exist, which serve to inhibit defensive (anterior-VMH) and offensive (posterior-VMH) intermale aggression, respectively.

The pain aggression induced by bronopol in the rat.

Abstract: Bronopol in doses of 7–25 mg/kg given intraperitoneally almost immediately releases a transitory aggressive behaviour in rats. The painful state caused by bronopol‐induced chemical peritonitis probably brought about this behavioural phenomenon. The age of the animal and also the reserpine treatment play some role in this behavioural pattern.

Effect of mother on the development of aggressive behavior in rats.

Young rats 23 days of age (Wistar strain) that are offspring of aggressive parents will attack mice. They kill them, however, only if the mother has already killed mice in their presence. Rats 30 days of age will kill mice spontaneously without any previous exposure to killing. The occurrence of muricide activity in young rats of this age is the same as in the adult population. If offspring of aggressive parents are reared by nonaggressive foster mothers from birth, they will not exhibit the muricide reaction at 30 days. In adulthood, however, the reaction appears to the same extent as in the offspring of aggressive parents reared by aggressive mothers. If the descendants of nonaggressive parents are reared by aggressive foster mothers from birth, 64.7% of them will kill mice at the age of 30 days. This aggression is retained in equal intensity during adulthood and cannot be attributed to specific learning in that the mothers have never encountered a mouse in the presence of their foster young.

Instrumental conditioning of aggressive behavior in rats

A method has been developed for bringing an aggressive response under stimulus control. It was found that the number of conditioned aggyessive responses was maximal when low-weight target rats were used. The latencies of the conditioned responses toward target animals of 124 gm were significantly lower than those toward animals of 221 and 284 gm. The application of an extinction procedure on the conditioned aggressive response substantially increased the total number of emitted aggressive responses.

Δ 9-tetrahydrocannabinol and aggressive behavior in rats

Fighting by pairs of albino rats, in a situation without painful shock, was measured by frequency or duration of dominant behaviors (biting attacks, threat postures, allogrooming, autogrooming), defensive-submissive behaviors (defensive-upright, submissive-supine and immobile-crouching postures), and mutual upright postures. Administration of Δ9-tetrahydro-cannabinol (1, 2, or 4 mg/kg, intraperitoneally) to the subordinate rat impaired the defensive-submissive behaviors, while the non-drugged dominant rat's biting attacks became more frequent and injurious. Administration of the drug to the dominant rat greatly reduced attacks and threats toward the non-drugged subordinate rat, and the dominance was weakened but not reversed.

Biogenic amines and their metabolism in the study of aggressive behaviour in rats

Publisher Summary This chapter discusses the biogenic amines and their metabolism in the study of aggressive behavior in rats. Various models of animal aggression may involve different central mechanisms and separate neurotransmitters. Alteration of serotonin metabolism with the tryptophan hydroxylase inhibitor para-chlorophenylalanine induced muricide in 9 of 34 rats when used in doses ranging from 100 mg/kg to 600 mg/kg. There were no conversions in the vehicle-treated group. Even though there were increases in footshock sensitivity in the pCPA-treated rats, their shock-induced fighting level changed insignificantly from 19 to 26–8%. In contrast, alteration predominantly of norepinephrine (NE) metabolism appears to greatly affect shock-induced fighting without altering the other models of aggression. Depletion of brain norepinephrine and dopamine and damage to central catecholamine nerve terminals with intracisternal 6-hydroxydopamine elevates shock induced fighting from a baseline level of 9.3% to 37.9%. This same effect can be achieved by treating rats with intraventricular injections of 6-hydroxydopa which depletes only brain norepinephrine.

Ultrasound and aggressive behaviour in rats and other small mammals

Aggressive behaviour has been observed in rats, Rattus norvegicus, and fourteen other species of small mammals. Ultrasounds were detected during aggressive behaviour in at least seven of these species, and in rats two distinct types of signal were recorded. Short ultrasounds of 3 to 65 ms duration and at frequencies of about 50 kHz were produced in aggressive situations, while long pulses up to 3400 ms duration and at about 25 kHz appeared to be synchronous with the long exhalations of submissive rats. Aggressive behaviour was reduced in encounters where long pulses were emitted. The physical characteristics of the ultrasounds produced by the different species are described and the importance of these signals in the establishment and maintenance of social relationships in small mammals is discussed.

Aggressive behaviour elicited in rats by Cannabis sativa: Effects of p-chlorophenylalanine and dopa

The influence of p-chlorophenylalanine (PCPA) and dihydroxyphenylalanine (DOPA) on aggressiveness elicited by marihuana in starved rats was studied. PCPA and DOPA potentiated several-fold this behavioural manifestation; the potentiation was still greater when the animals received both drugs. On the other hand, PCPA and DOPA alone or in combination, but without marihuana, failed to elicit aggressive behaviour in starved rats. Aggressiveness did not appear when rats fed ad libitum were treated with PCPA, DOPA and marihuana. The role played by starvation, PCPA and DOPA on the capability of marihuana to induce aggressive behaviour in rats is discussed.

The development of interspecies aggression of rats towards mice during lactation

Aggressive behavior of rats towards mice was tested in 4 breeding groups of laboratory female rats before mating and during lactation. On each testing day, independent groups of females were tested. The incidence of aggression before mating was at a low level for all the rats. During the period of lactation aggression increased significantly only in one group, namely the females of the Wistar-SPF group. In this group the aggressive behavior of mothers increased from parturition and reached its maximum on the fifth day of lactation (60 per cent of occurrence). Thereafter incidence of aggression decreased and disappeared entirely by the fifteenth day of lactation. This development is independent of the immediate presence of pups with mother, and of environment of the female during the time of testing. The aggressive behavior of the females who killed mice during the period of lactation had a long-term character, and outlasted the weaning of the pups.

Effect of lithium on foot shock aggression in rats.

LITHIUM has been shown to be effective in the treatment of mania1–3, and it reduces aggressive behaviour in Siamese fighting fish and small rodents4. I have investigated the action of lithium on aggressive behaviour in rats subjected to foot shock. This type of aggression has been well described already5,6.

Exploratory and aggressive behaviour in rats with and without experimental hypertension.

Rats from two strains, inbred for their sensitivity or resistance to experimental hypertension, showed marked differences in behaviour in certain standardized experimental situations. Rats from the re

Development of aggressive behavior in rats by chronic administration of cannabis sativa (marihuana)

Development of aggressive behavior in rats by chronic administration of cannabis sativa (marihuana)

The effect of FR response requirement on aggressive behavior in rats

Attack responses were observed in water-deprived rats that were exposed to FR-20, FR-40, and FR-60 water reinforcement schedules. Relative to the baseline condition, aggression increased under the FR-20 schedule. The frequency of attack behavior under the FR-40 and FR-60 conditions was equal to, or less than, the frequency of attack observed in the baseline condition. Attack responses were found to be equally probable in all segments of the interreinforcement intervals. These results were discussed with regard to the results of other studies of schedule-induced aggression.

Hoarding and aggressive behavior in rats.

Hoarding and aggressive behavior in rats.