Lesions in ventromedial part of amygdala impaired neither alimentary instrumental reflexes nor fo... more Lesions in ventromedial part of amygdala impaired neither alimentary instrumental reflexes nor food intake, but impaired predatory behavior. Lesions localized in the more dorsal and lateral part of the amygdala produced disorders in instrumental performance and food intake without changes in predatory attack. Both kind of lesions did not impair neurological reflexes, therefore the abolishment of predatory attack after ventromedial amygdala damage was not caused by sensory-motor disturbances. It is concluded that predatory behavior is based on specific mechanisms separate from both alimentary and instrumental ones.
The effect of imipramine treatment on the aggressive display and predatory dominance was tested i... more The effect of imipramine treatment on the aggressive display and predatory dominance was tested in 16 male cats yoked in 8 pairs. Imipramine applied chronically during 3 weeks in submissive cats produced a tendency to compete with the dominant cat in a predatory situation and an accompanying enhancement of aggressive display. Some of the treated cats gained the predatory dominance over previously dominant partners. The level of aggressiveness was not, however, directly related with the process of gaining dominance. Therefore it was concluded that imipramine enhances some mechanisms involved in dominance, not limited to aggression.
The behavior toward mouse was studied under and after chronic imipramine treatment in two groups ... more The behavior toward mouse was studied under and after chronic imipramine treatment in two groups of cats - non-killers and killers. Imiprarnine facilitated predatory behavior in the non-killers but not in the killers, which is in contrast to results obtained on rats. Imipramine produced a marked decrease of locomotor activity of non-killers tested in open field. The inhibition of locomotion did not interfere with the occurrence of killing behavior. It was concluded that imipramine selectively facilitates the neurophysiological mechanism of predatory behavior, which in cats might be connected with the reward system.
The effect of fear and relief from fear on heart rate (HR) was studied in partially restrained ad... more The effect of fear and relief from fear on heart rate (HR) was studied in partially restrained adult male rats. The emotional state was influenced behaviorally with the use of Pavlovian aversive conditioning procedure, and pharmacologically by injections of the selected anxiolytics and anxiogenics. A signal of danger (DS)--light or tone, preceded tail-shock (excitatory trials), while a signal of safety (SS), respectively tone or light, overlapped last 3s of 5s DS and predicted an omission of this expected aversive event (inhibitory trials). To assess the stability of HR changes to DS and SS we analyzed whether and how the experimental conditions (modality and position of signals, the ratio of numbers of excitatory to inhibitory trials in the session) influenced HR. HR changes to DS were different in pattern, stability and direction when compared to HR changes in response to SS. Reactions to DS, although accompanied mainly by conditioned bradycardia, were not consistent and depended on experimental conditions. However, the SS always evoked conditioned tachycardia. Anxiolitycs--benzodiazepines (diazepam and midazolam) and buspirone--influenced HR in nonconsistent manner. Anxiogenics--PTZ and FG7142 were without significant effects on HR. HR could not be trusted therefore as direct index of pharmacologically induced emotional states. The results are discussed in the context of possible biobehavioral meaning of HR changes in response to danger and safety and their reliability as fear/relief correlates.
The effect of the destruction of locus coeruleus noradrenergic (LC NA) projection on spontaneous ... more The effect of the destruction of locus coeruleus noradrenergic (LC NA) projection on spontaneous predatory attack, predatory competition and food intake was studied in cats. Selective noradrenergic neurotoxin DSP-4 injected into LC caused 71% decrease of noradrenaline content in amygdala and 41% decrease in hypothalamus. Predatory behaviour, predatory competition as well as food intake remained unchanged. It is concluded that LC NA projection is specifically involved neither in predation nor in food intake, which is in agreement with recent electrophysiological data.
Biological Influences on Aggression. Conceptual and Ethical Problems Raised by the Study of Brain... more Biological Influences on Aggression. Conceptual and Ethical Problems Raised by the Study of Brain-Behavior Relationships Underlying Aggression P. Karli. Is the Predatory Behavior a Model of Complex forms of the Human Aggression? J. Zagrodzka, E. Fonberg. The Role of Substance P Receptors in Amygdaloid Modulation of Aggressive Behavior in the Cat M.B. Shaikh, A. Siegel. Alcohol's Effects on Physiology and Aggression: What Is the Nature of the Link? P.F. Brain. Developmental Influences on Aggression. Learning Aggression from Models: From a Social Learning Towards a Cognitive Theory of Modeling B. Bjorkqvist. Attitudes Towards Violence and the Direction of the Development of a Child's Aggression L. Kirwil. Emotional Instability, Physical and Verbal Aggression and Prosocial Behavior as Precursors of Scholastic Achievement and Social Adjustment G.V. Caprara, et al. A Longitudinal Study of the Relationship between Aggressive and Depressive Tendencies in Elementary School Age Boys and Girls S. Feshbach, et al. Social Influences on Aggression. Poverty and Violence L.D. Eron, et al. Can Outfit Be Aggressive? Values and Images of Punks K. Lagerspetz.. Is a War a Consequence of Human Aggression R. Hinde. On the Determinants and Regulation of Impulsive Aggression L. Berkowitz. The Psychology of Aggression: Insights and Issues S. Feshbach. Index.
The effects of bicuculline methiodide administration into ventromedial hypothalamus (15 ng per si... more The effects of bicuculline methiodide administration into ventromedial hypothalamus (15 ng per site, bilaterally) on fear behavior and monoamines (NA, DA, 5-HT) and GABA in structures of the brain defensive system (hypothalamus, midbrain gray matter, amygdala, hippocampus and frontal cortex) were studied. Fear behavior was examined in the modified version of light-dark transition test. The time out from the illuminated compartment of chamber, the time spent there and number of returns to the illuminated compartment was measured. Additionally motor activity, i.e., number of crossings and rearings in dark as well as in the illuminated part of compartment, was registered. Blockade of GABAA receptors in the ventromedial hypothalamus resulted in increased fear behavior, i.e. decrease of time out from illuminated compartment and decrease of the time spent there. Motor behavior remained unchanged. HPLC analysis showed reduction of GABA concentration in all investigated brain structures. An increase of NA concentration in all examined structures with exception of the hypothalamus without effect on MHPG/NA was observed as well. Dopamine level remained unchanged, but DOPAC/DA ratio increased in all structures, except frontal cortex. Also HVA/DA ratio increased in the hypothalamus and midbrain. 5-HT concentration increased only in midbrain, 5-HIAA increased in midbrain and in frontal cortex, and 5-HIAA/5-HT ratio increased only in frontal cortex. These results indicate that GABA-ergic and monoaminergic systems remain in functional interactions and that these interactions may play an important role in the neurochemical regulation of fear behavior. The possible mechanism of GABA--monoaminergic interactions is discussed.
Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike atta... more Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike attack sometimes observed in rapid eye movement sleep without atonia (REM-A), created in cats by bilateral pontine lesions, was examined. Such lesions eliminate REM sleep skeletal muscle atonia and release elaborate behavior. Unilateral damage to the Ace alone increased affective defensive aggressive behavior toward humans and conspecifics without altering predatory behavior in wakefulness. Pontine lesions added at loci normally not leading to aggression induced predatorylike attacks in REM-A as well as the waking affective defense. Alterations of autonomic activity, the absence of relevant environmental stimuli in REM-A, or both may explain the state-related differences.
Male, adult cats were tested in three different experimental conditions which might lead to aggre... more Male, adult cats were tested in three different experimental conditions which might lead to aggressive display: (1) Cat-mouse interaction, (2) Predatory competition between two mice killers, (3) Conspecific interactions. DL-amphetamine in a dose of 1.5 mg/kg was administered every day for three weeks to one group of cats, whereas the other group was treated with saline. The following results were observed in amphetamine treated cats: (1) Inhibition or at least a prolonged latency of predatory attack, (2) loss of the dominant status, (3) total lack of offensive behavior and decrease of defensive postures. The results indicate that amphetamine in moderate doses acts to inhibit predatory attack and aggressive behavior in social situations.
Lesions in ventromedial part of amygdala impaired neither alimentary instrumental reflexes nor fo... more Lesions in ventromedial part of amygdala impaired neither alimentary instrumental reflexes nor food intake, but impaired predatory behavior. Lesions localized in the more dorsal and lateral part of the amygdala produced disorders in instrumental performance and food intake without changes in predatory attack. Both kind of lesions did not impair neurological reflexes, therefore the abolishment of predatory attack after ventromedial amygdala damage was not caused by sensory-motor disturbances. It is concluded that predatory behavior is based on specific mechanisms separate from both alimentary and instrumental ones.
The effect of imipramine treatment on the aggressive display and predatory dominance was tested i... more The effect of imipramine treatment on the aggressive display and predatory dominance was tested in 16 male cats yoked in 8 pairs. Imipramine applied chronically during 3 weeks in submissive cats produced a tendency to compete with the dominant cat in a predatory situation and an accompanying enhancement of aggressive display. Some of the treated cats gained the predatory dominance over previously dominant partners. The level of aggressiveness was not, however, directly related with the process of gaining dominance. Therefore it was concluded that imipramine enhances some mechanisms involved in dominance, not limited to aggression.
The behavior toward mouse was studied under and after chronic imipramine treatment in two groups ... more The behavior toward mouse was studied under and after chronic imipramine treatment in two groups of cats - non-killers and killers. Imiprarnine facilitated predatory behavior in the non-killers but not in the killers, which is in contrast to results obtained on rats. Imipramine produced a marked decrease of locomotor activity of non-killers tested in open field. The inhibition of locomotion did not interfere with the occurrence of killing behavior. It was concluded that imipramine selectively facilitates the neurophysiological mechanism of predatory behavior, which in cats might be connected with the reward system.
The effect of fear and relief from fear on heart rate (HR) was studied in partially restrained ad... more The effect of fear and relief from fear on heart rate (HR) was studied in partially restrained adult male rats. The emotional state was influenced behaviorally with the use of Pavlovian aversive conditioning procedure, and pharmacologically by injections of the selected anxiolytics and anxiogenics. A signal of danger (DS)--light or tone, preceded tail-shock (excitatory trials), while a signal of safety (SS), respectively tone or light, overlapped last 3s of 5s DS and predicted an omission of this expected aversive event (inhibitory trials). To assess the stability of HR changes to DS and SS we analyzed whether and how the experimental conditions (modality and position of signals, the ratio of numbers of excitatory to inhibitory trials in the session) influenced HR. HR changes to DS were different in pattern, stability and direction when compared to HR changes in response to SS. Reactions to DS, although accompanied mainly by conditioned bradycardia, were not consistent and depended on experimental conditions. However, the SS always evoked conditioned tachycardia. Anxiolitycs--benzodiazepines (diazepam and midazolam) and buspirone--influenced HR in nonconsistent manner. Anxiogenics--PTZ and FG7142 were without significant effects on HR. HR could not be trusted therefore as direct index of pharmacologically induced emotional states. The results are discussed in the context of possible biobehavioral meaning of HR changes in response to danger and safety and their reliability as fear/relief correlates.
The effect of the destruction of locus coeruleus noradrenergic (LC NA) projection on spontaneous ... more The effect of the destruction of locus coeruleus noradrenergic (LC NA) projection on spontaneous predatory attack, predatory competition and food intake was studied in cats. Selective noradrenergic neurotoxin DSP-4 injected into LC caused 71% decrease of noradrenaline content in amygdala and 41% decrease in hypothalamus. Predatory behaviour, predatory competition as well as food intake remained unchanged. It is concluded that LC NA projection is specifically involved neither in predation nor in food intake, which is in agreement with recent electrophysiological data.
Biological Influences on Aggression. Conceptual and Ethical Problems Raised by the Study of Brain... more Biological Influences on Aggression. Conceptual and Ethical Problems Raised by the Study of Brain-Behavior Relationships Underlying Aggression P. Karli. Is the Predatory Behavior a Model of Complex forms of the Human Aggression? J. Zagrodzka, E. Fonberg. The Role of Substance P Receptors in Amygdaloid Modulation of Aggressive Behavior in the Cat M.B. Shaikh, A. Siegel. Alcohol's Effects on Physiology and Aggression: What Is the Nature of the Link? P.F. Brain. Developmental Influences on Aggression. Learning Aggression from Models: From a Social Learning Towards a Cognitive Theory of Modeling B. Bjorkqvist. Attitudes Towards Violence and the Direction of the Development of a Child's Aggression L. Kirwil. Emotional Instability, Physical and Verbal Aggression and Prosocial Behavior as Precursors of Scholastic Achievement and Social Adjustment G.V. Caprara, et al. A Longitudinal Study of the Relationship between Aggressive and Depressive Tendencies in Elementary School Age Boys and Girls S. Feshbach, et al. Social Influences on Aggression. Poverty and Violence L.D. Eron, et al. Can Outfit Be Aggressive? Values and Images of Punks K. Lagerspetz.. Is a War a Consequence of Human Aggression R. Hinde. On the Determinants and Regulation of Impulsive Aggression L. Berkowitz. The Psychology of Aggression: Insights and Issues S. Feshbach. Index.
The effects of bicuculline methiodide administration into ventromedial hypothalamus (15 ng per si... more The effects of bicuculline methiodide administration into ventromedial hypothalamus (15 ng per site, bilaterally) on fear behavior and monoamines (NA, DA, 5-HT) and GABA in structures of the brain defensive system (hypothalamus, midbrain gray matter, amygdala, hippocampus and frontal cortex) were studied. Fear behavior was examined in the modified version of light-dark transition test. The time out from the illuminated compartment of chamber, the time spent there and number of returns to the illuminated compartment was measured. Additionally motor activity, i.e., number of crossings and rearings in dark as well as in the illuminated part of compartment, was registered. Blockade of GABAA receptors in the ventromedial hypothalamus resulted in increased fear behavior, i.e. decrease of time out from illuminated compartment and decrease of the time spent there. Motor behavior remained unchanged. HPLC analysis showed reduction of GABA concentration in all investigated brain structures. An increase of NA concentration in all examined structures with exception of the hypothalamus without effect on MHPG/NA was observed as well. Dopamine level remained unchanged, but DOPAC/DA ratio increased in all structures, except frontal cortex. Also HVA/DA ratio increased in the hypothalamus and midbrain. 5-HT concentration increased only in midbrain, 5-HIAA increased in midbrain and in frontal cortex, and 5-HIAA/5-HT ratio increased only in frontal cortex. These results indicate that GABA-ergic and monoaminergic systems remain in functional interactions and that these interactions may play an important role in the neurochemical regulation of fear behavior. The possible mechanism of GABA--monoaminergic interactions is discussed.
Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike atta... more Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike attack sometimes observed in rapid eye movement sleep without atonia (REM-A), created in cats by bilateral pontine lesions, was examined. Such lesions eliminate REM sleep skeletal muscle atonia and release elaborate behavior. Unilateral damage to the Ace alone increased affective defensive aggressive behavior toward humans and conspecifics without altering predatory behavior in wakefulness. Pontine lesions added at loci normally not leading to aggression induced predatorylike attacks in REM-A as well as the waking affective defense. Alterations of autonomic activity, the absence of relevant environmental stimuli in REM-A, or both may explain the state-related differences.
Male, adult cats were tested in three different experimental conditions which might lead to aggre... more Male, adult cats were tested in three different experimental conditions which might lead to aggressive display: (1) Cat-mouse interaction, (2) Predatory competition between two mice killers, (3) Conspecific interactions. DL-amphetamine in a dose of 1.5 mg/kg was administered every day for three weeks to one group of cats, whereas the other group was treated with saline. The following results were observed in amphetamine treated cats: (1) Inhibition or at least a prolonged latency of predatory attack, (2) loss of the dominant status, (3) total lack of offensive behavior and decrease of defensive postures. The results indicate that amphetamine in moderate doses acts to inhibit predatory attack and aggressive behavior in social situations.
Uploads
Papers