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PubMed1983

Safety training: the elimination of avoidance-motivated aggression in dogs.

This study sought to identify the behavioral characteristics and appropriate treatment of a form of instrumental aggression in companion dogs, herein recognized as avoidance-motivated aggression. In Experiment 1, retrospective data on 92 cases of dangerously aggressive dogs demonstrated the avoidance nature of the aggressive response and its intractability to established counterconditioning treatments. In Experiment 2, safety training, a modified avoidance-learning procedure, resulted in complete and permanent elimination of aggression in all of the 36 dogs tested. In addition, it produced extremely extinction-resistant prosocial avoidance responses, significant increases in the dogs' emotional stability, an avoidance-learning and safety acquisition response set, and improvements in measures of the dog's "carriage." Experiment 3 showed how effective safety training is when compared with other behavior modification techniques that, in theory, should have an impact on avoidance-motivated aggression. Experiment 4 demonstrated the critical importance of using the conditioned safety cue as a positive reinforcement. The relationship of avoidance-motivated aggression to other forms of aggression is discussed. The success of safety training compared with the failure of electrical aversion therapy is analyzed. The theoretical concepts of behavioral balance and an avoidance-learning set are presented. Suggestions to improve the effectiveness of counterconditioning for human avoidance-motivated pathologies are offered. All in all, the data seem to suggest that safety training may create in dogs a sense of control over environmental stressors. By teaching the dogs a behaviorally balanced battery of prosocial "coping" responses, they may be developing the canine counterpart of "self-efficacy" or "courage." It is suggested that this cognitive modification may provide the antithesis of "learned helplessness" and may be of prime importance to the success and stability of the results.

Accident Prevention↗

PubMed2002

Limbic thalamic lesions, appetitively motivated discrimination learning, and training-induced neuronal activity in rabbits.

A substantial literature implicates the anterior and mediodorsal (limbic) thalamic nuclei and the reciprocally interconnected areas of cingulate cortex in learning, memory, and attentional processes. Previous studies have shown that limbic thalamic lesions severely impair discriminative avoidance learning and that they block development of training-induced neuronal activity in the cingulate cortex. The present study investigated the possibility that the limbic thalamus and cingulate cortex are involved in reward-based discriminative approach learning, wherein head-extension responses yielding oral contact with a drinking spout that was inserted into the conditioning chamber after a positive conditional stimulus (CS+) were reinforced with a water reward but responses to the spout after a negative conditional stimulus (CS-) were not reinforced. In this task, the rabbits learned primarily to omit their prepotent responses to the spout on CS- trials. Acquisition was severely impaired in rabbits given limbic thalamic lesions before training. As during avoidance learning, posterior cingulate cortical neurons of control rabbits developed learning-related neuronal responses to task-relevant stimuli, but this activity was severely attenuated in rabbits with lesions. These results support a general involvement of the cingulothalamic circuitry in instrumental approach and avoidance learning. The fact that learning consisted of response omission indicated that the cingulothalamic role is not limited to acquisition or production of active behavioral responses, such as locomotion. It is proposed that cingulothalamic neurons mediate associative attention, wherein enhanced neuronal responses to stimuli associated with reinforcement facilitate the selection and production of task-relevant responses.

Acoustic Stimulation↗

PubMed1986

Changes in avoidance behaviour following ethanol treatment in rats of different ages.

Avoidance learning and pain sensitivity were studied in rats after chronic ethanol administration (1.1 to 1.7 g per kg b.w. in drinking water) at prenatal, adolescent and adult ages. The behavioural reactions were tested in adulthood by studying passive and active avoidance learning and the threshold of pain sensitivity to electric tail shock. Chronic ethanol consumption led to an impairment of avoidance learning and to hyperalgesia in each experimental series, although the alterations were greater in the prenatally treated groups. The experimental observations are discussed in the light of fetal alcohol syndrome.

Alcoholism↗

PubMed1999

A selective genetic analysis of the Syracuse high- and low-avoidance (SHA/Bru and SLA/Bru) strains of rats (Rattus norvegicus).

Selective breeding of Long-Evans rats for good and poor avoidance learning in a two-way shuttle box resulted in the Syracuse strains that differ markedly in the selected phenotypes. These phenotypes have many associated traits, five of which are studied here: emotionality (open-field defecation), Pavlovian fear conditioning (CER suppression), passive avoidance training (punishment), size (weight) of the adrenal glands and adrenal concentration of corticosterone. Specifically, animals of the low-avoidance strain are more emotional, show greater fear conditioning, exhibit faster passive avoidance learning, and have larger adrenal glands in which adrenal corticosterone levels are lower than those of the high-avoidance strain. A reciprocal dihybrid cross of the two strains produced F1 hybrids, which were used to produce the segregating second filial and high and low backcross generations from which animals displaying the extreme high- and low-avoidance phenotypes were selected for study of the associated traits. Measurement of the five traits in these high and low phenotypic animals indicated that all five remain significantly associated with the avoidance phenotypes, in the expected direction, and comparably in all three segregating generations. The results indicate that the hypothesis of a major gene controlling avoidance learning must be rejected and that the few (2-3) genetic units thought to be involved may be closely linked to those that mediate these five associated characters, or express all five pleiotropically.

Adrenal Glands↗

PubMed2004

Learning obstacle avoidance with an operant behavior model.

Artificial intelligence researchers have been attracted by the idea of having robots learn how to accomplish a task, rather than being told explicitly. Reinforcement learning has been proposed as an appealing framework to be used in controlling mobile agents. Robot learning research, as well as research in biological systems, face many similar problems in order to display high flexibility in performing a variety of tasks. In this work, the controlling of a vehicle in an avoidance task by a previously developed operant learning model (a form of animal learning) is studied. An environment in which a mobile robot with proximity sensors has to minimize the punishment for colliding against obstacles is simulated. The results were compared with the Q-Learning algorithm, and the proposed model had better performance. In this way a new artificial intelligence agent inspired by neurobiology, psychology, and ethology research is proposed.

Avoidance Learning↗

PubMed1995

The effect of archistriatal lesions on 'open field' and fear/avoidance behaviour in the domestic chick.

The chick archistriatum has been implicated in avoidance learning and filial imprinting. However, its role in these learning paradigms may be due to the inhibition of normal avoidance responses, since the avian archistriatum has been shown to play a role in fear/avoidance behaviour. The involvement of the archistriatum in the expression of unlearned fear/avoidance behaviour was therefore investigated in two day-old chicks. Chicks were exposed individually to a novel 'open field' for 5 min. Behaviour was recorded on videotape for analysis. In a separate but concurrent experiment, bilateral archistriatal lesions, sham archistriatal lesions or lateral cerebral lesions were made in day-old chicks which were then exposed to the 'open field' arena. At the end of each exposure a novel object was dropped near the chick. Chicks with archistriatal lesions generally displayed greater movement, more pecking behaviour and spent more time near the centre of the 'open field' than other chicks. There were no differences between the treatment groups in latencies to move or begin peeping. The behaviour of untreated chicks in the 'open field' was similar to that of sham-lesioned chicks and there was no effect of hatch on behaviour. Upon exposure to a novel object, indices of fear and avoidance were not changed in lesioned chicks. These results demonstrate that in the young chick, the archistriatum may be involved in the response to mild or intermediate levels of environment or isolation-related stress, but does not appear to be important for overt fear responses or avoidance of novel objects. Taken together with the results of previous work, the data suggests that the archistriatum may be directly involved in avoidance learning and imprinting.

Animals↗

PubMed1984

Vasopressin effect on learning in 6-hydroxydopamine-pretreated rats: correlation with caudate vasopressin levels.

Conditioned avoidance learning was studied at 2 months of age in rats treated with intracisternal 6-OH dopamine (DA) at 5 days of life after desipramine pretreatment. Subcutaneous DDAVP 20 micrograms/rat or LVP 1 microgram/rat improved conditioned avoidance learning in the 6-OH DA-treated rats at least as much as in control rats. Caudate vasopressin levels significantly correlated with learning ability in the shuttle box in control rats (r = 0.69, n = 8), 6-OH DA-treated rats (r = 0.64, n = 8), 6-OH DA plus DDAVP-treated rats (r = 0.60, n = 9), or in the total sample (r = 0.59, n = 25, p less than 0.01).

Animals↗

PubMed1992

Behavior, ectopias and immunity in BD/DB reciprocal crosses.

In a previous study, in which fertilized DBA ova were transferred into an autoimmune female, and NZB ova were transferred into a non-autoimmune female, we found that (1) the maternal environment affected the degree of autoimmunity, (2) the incidence of cortical ectopias was not affected by the maternal environment (3) DBA and NZB females had greater paw asymmetry if reared in an autoimmune uterus, and (4) avoidance learning scores were inversely related to degree of autoimmunity. In the present experiment, reciprocal crosses of DBA and BXSB mice were studied to confirm and extend the original findings. DB mice (DBA female x BXSB male) had greater immune activity than the BD animals, had poorer avoidance learning, but were better on black-white discrimination learning and the Lashley III maze. The BD mice had greater paw asymmetry. Only one of 38 animals had a cortical ectopia. The results lead to the following conclusions: (1) there is an inverse relationship between amount of immune activity and active avoidance learning; (2) some uterine factor in autoimmune mice causes females to have greater paw asymmetry; (3) cortical ectopias are under genetic control; and (4) the lesser immune activity of the BD mice suggests that they developed a suppressor system following early exposure to autoimmunity in the uterine/maternal environment.

Animals↗

PubMed1984

Beneficial effect of idebenone (CV-2619) on cerebral ischemia-induced amnesia in rats.

An experimental model of amnesia induced by cerebral ischemia after one-trial passive avoidance learning was established to test the effects of a novel compound, 6-(10-hydroxydecyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (idebenone, CV-2619), and some commonly used drugs in rats. One day after the vertebral artery was electrocauterized bilaterally, the common carotid artery was transiently occluded bilaterally to produce cerebral ischemia. The amnesia was estimated by the response latency for a rat to step from a light safety compartment to a dark compartment in which a foot-shock was given. The results of the retention test given 24 hr after the ischemia indicated that amnesia was successfully produced when the 200-600 sec ischemia was provided within 20 min after the avoidance learning. The effects of drugs on the amnesia induced by a 200-sec ischemia immediately after the avoidance learning were as follows: CV-2619 (10, 30 mg/kg, i.p. or p.o.) given before the retention test significantly increased the response latency, indicating a reversal effect on the amnesia. Physostigmine (0.1, 0.2 mg/kg, i.p.) and arginine-vasopressin (10 micrograms/kg, s.c.) were also effective, and calcium hopantenate (500 mg/kg, p.o.) showed a slight reversal action. Furthermore, CV-2619 (10 mg/kg, i.p.), given before or after the ischemia, significantly inhibited the appearance of amnesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnesia↗

PubMed1975

Rapid acquisition of discrete-trial lever-press avoidance: effects of signal-shock interval.

Acquisition of discrete-trial lever-press avoidance learning was studied in three experiments. Experiment I compared a new training procedure, which produces rates of lever-press avoidance learning comparable to those obtained in shuttle boxes, with a "conventional", less efficient training procedure. A factorial design was used to compare continuous versus intermittent shock and a long-variable versus a short-fixed signal-shock interval. Learning was best in the groups trained with the long and variable interval and poorest in those trained with the short and fixed interval. Type of shock had no effect. Experiment II separated the effects of duration from those of variability of the signal-shock interval. Fixed and variable intervals of 10 and 60 sec were tested and duration was the only significant factor. Experiment III addressed the effect of the differential opportunity to avoid provided by long signal-shock intervals by varying this interval from 10 to 60 sec in 10-sec steps. Only the 10-sec group showed slow acquisition relative to the others. Analysis of avoidance response latencies showed that the distributions for all groups were positively skewed and that skewness increased with increasing duration of the signal-shock interval. At intervals longer than 20 sec, the animals made progressively less use of their increased opportunity to respond. The data do not support the opportunity-to-respond interpretation of the effects of duration of signal-shock interval and suggest that some type of inhibitory process may block lever-press avoidance learning at intervals as short as 10 sec. The significance of these findings for species-specific defense reaction and preparedness theories was emphasized.

Journal Article↗

PubMed1996

Nitric oxide but not carbon monoxide is involved in spatial learning of mice.

The aim of the present study was to elucidate the role of carbon monoxide (CO) in learning and to compare it with that of nitric oxide (NO). Effects of an inhibitor of heme oxygenase which produces CO, Zn-protoporphyrin IX, on passive avoidance learning and spatial learning in mice were examined using step through, step down and water maze tests. Zn-protoporphyrin IX (10, 20 nmol, i.c.v.) affected neither type of learning. In contrast, N-omega-nitro-L-arginine (40 nmol, i.c.v.), an inhibitor of NO synthase, impaired spatial learning, but not passive avoidance learning. These results suggest that NO but not CO is involved in spatial learning.

Animals↗

PubMedDate not supplied

Effect of sulfite on cognitive function in normal and sulfite oxidase deficient rats.

Sulfites, which are commonly used as preservatives, are continuously formed in the body during metabolism of sulfur-containing amino acids. Sulfite is oxidized to sulfate ion by sulfite oxidase (SOX, EC. 1.8.3.1). The aim of this study was to investigate the possible toxic effects of sulfite on neurons by measuring active avoidance learning in normal and SOX-deficient rats. For this purpose, male albino rats used in this study were divided into eight groups such as control group (C), sulfite group (25 mg/kg) (S), vitamin E group (50 mg/kg) (E), sulfite (25 mg/kg)+vitamin E group (50 mg/kg) (SE), SOX-deficient group (D), deficient+vitamin E group (50 mg/kg) (DE), deficient+sulfite group (25 mg/kg) (DS) and deficient+sulfite (25 mg/kg)+vitamin E group (50 mg/kg) (DSE). Sulfite-induced impairment of active avoidance learning in SOX-deficient rats but not in normal rats. Sulfite had no effect on hippocampus TBARS levels in SOX normal groups. In SOX-deficient rats, TBARS levels were found to be significantly increased with sulfite exposure. Vitamin E reversed the observed detrimental effects of sulfite in the SOX-deficient rats on their hippocampal TBARS but not on their active avoidance learning. In conclusion, sulfite has neurotoxic effects in sulfite oxidase deficient rats, but this effect may not depend on oxidative stress.

Animals↗

PubMed2002

Endomorphins 1 and 2 induce amnesia via selective modulation of dopamine receptors in mice.

The involvement of dopamine receptors in the amnesic effects of the endogenous micro-opioid receptor agonists endomorphins 1 and 2 was investigated by observing step-down type passive avoidance learning in mice. Although the dopamine D1 receptor agonist R(+)-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-7,8-diol hydrochloride (R(+)-SKF38393) (0.05 and 0.1 mg/kg), the dopamine D1 receptor antagonist R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (R(+)-SCH23390) (2.5 and 5 microg/kg) or the dopamine D2 receptor agonist N-n-phenethyl-N-propylethyl-p-(3-hydroxyphenyl)-ethylamine (RU24213) (0.3 and 1 mg/kg) had no significant effects on the endomorphin-1 (10 microg)- or endomorphin-2 (10 microg)-induced decrease in step-down latency of passive avoidance learning, (-)-sulpiride (10 mg/kg), a dopamine D2 receptor antagonist, significantly reversed the decrease in step-down latency evoked by endomorphin-2 (10 microg), but not by endomorphin-1 (10 microg). Taken together, it is likely that stimulation of dopamine D2 receptors results in the endomorphin-2-but not endomorphin-1-induced impairment of passive avoidance learning.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMedDate not supplied

The biochemistry of learning and memory.

An overview of some of the biochemical and molecular events involved in the process of learning and memory are presented in a short review. Two invertebrate models of learning are considered: the gill-withdrawal reflex of Aplysia and avoidance learning in Drosophila melanogaster. Particular attention is paid to the biochemical mechanisms underlying both the development of long-term potentiation (LTP) and passive avoidance learning (PAL) in the young chick. The role of several biological molecules in learning and memory are considered, for example, protein kinase C (PKC), Ca(++)-Calmodulin kinase II (CaMKII), GAP-43, and glutamate receptors.

Adenylyl Cyclases↗

PubMed1975

Activity and learning in neonatally hormone treated rats.

The degree of activity and the performance in active avoidance learning were determined in adulthood, from neonatal hormone treated and intact rats. The treated groups were androgenized females and castrated males and females. Normal males and females composed the intact groups. Activity was measured in two tests situations, i.e., open field and shuttle box. Similar results were obtained in both tests, and a positive correlation coefficient was found between them. Intact females showed more activity than males; castration and testosterone injection in females decreased their activity. On the contrary, castration in males increased it. The effects of the treatments on the performance in the active avoidance task were similar to those described for activity, with the only exception that castration in males did not produce a significant effect in this test. Nevertheless, no correlation was found between activity and avoidance learning scores. The validity of the classification of different types of behavior as sexual or non-sexual is discussed.

Animals↗

PubMed2000

Long-term effects of prenatal stress experiences and postnatal maternal separation on emotionality and attentional processes.

Postnatal environmental manipulations naturally occur on the background of prenatal experiences. In the laboratory rat, both pre- and postnatal environmental manipulations have been shown to alter adult behaviour. Additionally, it has been demonstrated that the consequences of postnatal manipulations can be altered by previous prenatal stress experience (PS). In the present study, we investigated long-term behavioural consequences of combined PS and postnatal experience, namely repeated maternal separation (MS). PS primarily increases emotionality and fear-related behaviour, while postnatal repeated MS has been previously reported to affect primarily attentional processes. Thus, we tested adult male and female Wistar rats on paradigms involving both emotionality and attention, namely open field, prepulse inhibition (PPI), and latent inhibition (LI) in the active avoidance and the conditioned emotional response paradigms. In line with previous reports, PS decreased open-field locomotion and impaired avoidance learning (increased emotionality), while MS enhanced LI (selective attention) and improved avoidance learning. Further, PS also increased PPI. There was little interaction between the two manipulations: The increased PPI seen after PS was normalised by MS, and the MS-induced enhancement of LI (using the active avoidance paradigm) was not evident in subjects previously subjected to PS. Taken together, these results suggest that the effects of PS and repeated MS are not synergistic in any of the investigated paradigms but can antagonise each other. Thus, in assessing the effects of postnatal manipulations, attention should be paid to the inadvertent occurrence of prenatal stress.

Animals↗

PubMed1986

Influence of the varieties of differentiation training and prefrontal lesions on retention and reversal learning of avoidance responding in dogs.

The postoperative retention and reversal of go, no-go avoidance reflex differentiation with symmetrical and asymmetrical reinforcement were studied in dogs with prefrontal lesions and unoperated controls. The general pattern of the influence of such experimental variables as type of differentiation task an,d quality and arrangement of conditioned stimuli' was similar to that oberved preoperatively. However, prefrontal surgery changed the interactions between these experimental variables. The modifying role of the medial and the lateral parts of prefrontal cortex on the retention of differentiation and on reversal learning is discussed.

Acoustic Stimulation↗

PubMed1986

Effects of prenatal alcohol exposure on behavior of aged rats.

Pregnant rats were intubated with alcohol (3.5 g/kg, twice daily) on gestation days 11-21. Control animals were intubated with an isocaloric sucrose solution and were pair-fed and pair-watered to alcohol-treated dams. At birth, offspring were placed with non-treated surrogate dams. When animals were slightly more than 1 year of age, they were tested for passive avoidance learning, spontaneous alternation and activity. Groups did not differ in passive avoidance learning or spontaneous alteration but animals prenatally exposed to alcohol were more active than controls. Additional studies showed that this increased activity was not affected by testing animals in the presence of environmental stimuli such as objects which could be manipulated, or by odors from mouse shavings from male and female mice.

Animals↗