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At least 1,693 records · Page 94Linked to original sources
PubMed1998

Behavioural profiles of two Wistar rat lines selectively bred for high or low anxiety-related behaviour.

Over the past years, two breeding lines, derived originally from outbred Wistar rats, have been established that differ markedly and consistently in their anxiety-related behaviour in the elevated plus-maze. At the age of ten weeks, rats were tested once on the elevated plus-maze and the males and females displaying the most anxious and the least anxious behaviour were sib-mated to start a new generation of the high anxiety-related behaviour (HAB) and the low anxiety-related behaviour (LAB) lines, respectively. The resulting difference in emotionality between these two lines was also evident in an open field test and correlated with differences in the forced swim test. In the open field, the HAB rats tended to be less active and explored the central zone of the open field much less than the LAB animals. In the forced swim test, HAB rats started floating earlier, spent significantly more time in this immobile posture and struggled less than LAB rats. However, in an olfactory-cued social discrimination task there was no difference between male and female animals from either line. The overall performance in these various behavioural tests suggests that selective breeding has resulted in rat lines not only differing markedly in their innate anxiety-related behaviour in the plus-maze, but also in other stress-related behavioural performances, suggesting a close link between the emotional evaluation of a novel and stressful situation and an individual's coping strategy.

Animals↗
PubMed1995

"Try it. You'll like it." Effects of information on willingness to try novel foods.

Three experiments are reported on the effects of "taste" or nutrition information on willingness to try novel foods. "Taste" information improved responses to four out of the five foods examined. There was a consistent, but not statistically significant, trend for nutritional information to be effective. In experiment I, conducted with 3- to 8-year-old children in a laboratory setting, and in experiment II, conducted with 10- to 20-year-olds in a cafeteria, there were strong age effects. Older subjects responded more positively to novel foods than did younger subjects. There were no significant interactions between information and age and there were no sex differences. It is commonly assumed that novel foods are rejected because they are thought to be dangerous. However, the fact that dangerous foods are good tasting should be irrelevant to willingness to taste them. Our results are consistent with the idea that, in settings like laboratories and cafeterias, culture has already defined foods as being safe. Perhaps rejection in such settings is based on fear of a negative sensory experience.

Adolescent↗
PubMed2001

The effects of oral selegiline hydrochloride on learning and training in the dog: a psychobiological interpretation.

1. Twenty two healthy, non-problem dogs were assessed for their acquisition of three different learning tasks on consecutive days and on the extinction of the response in the third. In Task 1, dogs were trained to walk in a circle on command. In Task 2, dogs were trained to retreat and sit on a mat. In Task 3, dogs were assessed for the acquisition and extinction of an operant response (pawing a panel). 2. Dogs were orally administered a placebo or selegiline hydrochloride at a dose of 0.5 mg/kg for a period of three weeks prior to testing and during the test period. 3. Dog's treated with selegiline tended to perform better at tasks which were clearly lured with a motivationally significant cue, performing a first correct response sooner and requiring fewer reinforcements to reach the success criterion. They were also significantly more likely to walk over a novel object placed on the floor of the test arena. In the absence of a significant lure, the selegiline treated dogs took significantly longer to reach the required performance criterion for the operant task. These dogs also extinguished their response more rapidly than the control group 4. In the third task, selegiline treated dogs were significantly less likely to look away and throughout all tasks these dogs tended to be less distracted than the placebo group. 5. These findings and other reports associated with the effects of selegiline on learning may be explained by reference to the effects of selegiline on dopaminergic structures associated with positive incentive motivation.

Administration, Oral↗
PubMed1999

Early behavioral changes after nigro-striatal system damage can serve as predictors of striatal dopamine depletion.

1. Rats which had received a unilateral injection of 6-OHDA into the substantia nigra were assigned to four lesion groups according to the degree of DA depletion in the neostriatum. In these animals, behavioral changes in the open-field were investigated during the first postoperative week. Overall, this analysis showed that the animals could adequately be characterized by behavior on day 1 and day 7 after lesion. 2. On the first day after lesion, the groups with the severest DA depletions (> 80% and 55-80%) showed an ipsilateral asymmetry in turning. After one week, these groups showed a tendency to recover from this deficit; however, the group with the most strongest lesions (> 80%) was still asymmetric. 3. In scanning behavior, in contrast to turning, all the lesion groups displayed an initial ipsilateral asymmetry. On day 7 after lesion, only the group with DA depletions of > 80% still had an ipsilateral asymmetry. Locomotor activity and rearing were initially reduced after lesion, and showed a tendency to recover, especially in the group with the most severe DA depletions (> 80%). There were no differences between groups neither on day 1 nor on day 7 by grooming, but this behavior increased in all the lesion groups with time. 4. The correlational analyses yielded a positive relationship between the asymmetry in turning and neostriatal DA depletion. Locomotor activity and rearing on day 1 were both negatively correlated with DA depletion. The present results show that a number of behavioral parameters obtained in the open-field are affected by unilateral lesions of the nigro-striatal DA system. The degree of deficit, its time course and relation to lesion size differs among the various behavioral measures. Some of these early behavioral changes after unilateral nigrostriatal lesion are related to DA depletion and should therefore be useful to predict lesion size.Together, these data suggest that the study of such behavioral changes can provide an important tool, to investigate the compensatory mechanisms underlying striatal DA depletion and to understand preclinical states of the Parkinson's disease.

Animals↗
PubMed2001

Increased social fear and decreased fear of objects in monkeys with neonatal amygdala lesions.

The amygdala has been implicated in the mediation of emotional and species-specific social behavior (Kling et al., 1970; Kling and Brothers, 1992; Kluver and Bucy, 1939; Rosvold et al., 1954). Humans with bilateral amygdala damage are impaired in judging negative emotion in facial expressions and making accurate judgements of trustworthiness (Adolphs et al., 1998, 1994). Amygdala dysfunction has also been implicated in human disorders ranging from social anxiety (Birbaumer et al., 1998) to depression (Drevets, 2000) to autism (Bachevalier, 1994; Baron-Cohen et al., 2000; Bauman and Kemper, 1993). We produced selective amygdala lesions in 2-week-old macaque monkeys who were returned to their mothers for rearing. At 6-8 months of age, the lesioned animals demonstrated less fear of novel objects such as rubber snakes than age-matched controls. However, they displayed substantially more fear behavior than controls during dyadic social interactions. These results suggest that neonatal amygdala lesions dissociate a system that mediates social fear from one that mediates fear of inanimate objects. Furthermore, much of the age-appropriate repertoire of social behavior was present in amygdala-lesioned infants indicating that these lesions do not produce autistic-like behavior in monkeys. Finally, amygdala lesions early in development have different effects on social behavior than lesions produced in adulthood.

Aging↗
PubMed1997

Discriminated approach-avoidance task--a new paradigm for measuring both appetitive and aversive memory processes under identical test conditions.

Research on mnemonic processes in rats has predominantly made use of either appetitively or aversively motivated tasks. These behavioral paradigms are popular because rats are easily trained and a range of stimuli and response alternatives are available. Also, these paradigms have been generally found to be sensitive to pre- and post-trial manipulations with a variety of drugs having hypo- and hypermnesic effects. However, the available procedures do not permit a qualitative analysis of the memory changes, namely, a dissociation between the effect of a compound under study on the memory for pleasant versus unpleasant events, under the same experimental conditions. The discriminated approach-avoidance paradigm presented here is a novel method that enables this to be investigated quite easily, in rats. This behavioral paradigm was developed originally to assess the retrieval bias in the learned helplessness condition, and subsequently has been employed in studies of the pharmacological effects of several stress-related neuropeptides on appetitive and aversive memory processes.

Animals↗
PubMed2000

Eating disorders and substance use. An examination of behavioral associations.

The association between the eating disorders of anorexia nervosa (AN) and bulimia nervosa (BN) and substance use disorder (SUD) has been widely investigated, however, our understanding of the relationship between the disorders remains unclear. Explanatory models have tended to focus on behaviors, yet, little is currently known about the patterns of association among disordered eating and substance use behaviors. In this exploratory study, a behavioral approach was used to investigate the cooccurrence of seven disordered eating and three substance use behaviors in women meeting current DSM-III-R criteria for AN (n=12), subthreshold AN (n=14), BN (n=29), and subthreshold BN (n=24). Results suggest that disordered eating behaviors are differentially associated with substance use behaviors. The most robust finding was that diuretic use positively predicted the current level of alcohol use regardless of diagnostic group. The findings for marijuana and tobacco use were less consistent. Results suggest that rather than being pervasive in all eating disordered women, higher levels of alcohol use may be found in those women who use diuretics.

Journal Article↗
PubMedDate not supplied

Behavioral characteristics of mice with genetic knockout of monoamine oxidase type A.

Transgenic mice of line Tg8 were used to study the effects of deletion of the monoamine oxidase type A gene and the absence of the corresponding enzyme on behavior. These experiments showed that Tg8 mice with genetic knockout of monoamine oxidase type A differed from mice of the parental line C3H/HeJ by lower levels of the startle reflex in response to an acoustic signal, while there was no difference in the prestimulus inhibition of the startle response. Tg8 mice showed decreased investigative activity and decreases in the number of sector crossings in the light-dark anxiety test. There were significant increases in aggression as a motivation in male Tg8 mice, which was manifest as an increase in the number of mice demonstrating aggression and a decrease in the latent period of attack. The intensity of aggression changed to a lesser extent - the number of fights even decreased, though longer periods of keeping mice together resulted in increased numbers of deaths among intruder mice. At the same time, there were no significant differences between mice with genetic knockout of monoamine oxidase type A and control mice in terms of the expression of sexual activation: the behavioral responses of Tg8 males to presentation of females was marked and was no different from that of male C3H/HeJ mice. Knockout of the gene had no effect on movement activity on behavior in an elevated cross-shaped maze or in the test for predisposition to catalepsy.

Aggression↗
PubMed2003

Anxiolytic effect of Proproten under conditions of punished and unpunished behavior.

The anxiolytic effect of Proproten containing potentiated antibodies to brain-specific S100 protein (2.5 ml/kg) in male outbred albino rats was studied under conditions of punished (Vogel's conflict situation with pain stimulation) and unpunished behavior (elevated plus-maze and open-field tests). Proproten significantly increased the incidence of punished drinking in the conflict situation with pain stimulation, number of entries, and time spent in the open arms of the elevated plus-maze and decreased the rate of defecation and urination. In the open-field test Proproten induced entries of rats into the center of an illuminated area. Proproten was efficient after single administration and course of treatment (2 times a day, 5 days). These results show that Proproten produces the anxiolytic effect under conditions of punished and unpunished behavior.

Animals↗
PubMed2004

Spatial arrangement of odor sources modifies the temporal aspects of crayfish search strategies.

In natural habitats, animals encounter cues from multiple odor sources that may impact foraging decisions. Previous work has focused on orientation behavior to one food odor source, and does not distinguish between mechanosensory and chemosensory guidance of orientation. The present study investigated how the spatial distribution of two food cues affects crayfish orientation behavior. Crayfish, Orconectes virilis, were presented with odor sources that were separated in an artificial stream. Orientation behavior was filmed from above and digitized at a rate of 1 frame per sec. Electrochemical recordings were taken to characterize the odor plume, and an acoustic doppler velocimeter was used to characterize the hydrodynamic structure of the artificial stream. Temporal changes in odor plume structure were seen as a result of the positioning of the odor sources. Changes in the intermittency of the odor pulses as well as concentration, rise time, and slope of the pulse were observed. Time series analysis showed that the lower frequency signals of the dual odor source were higher in energy than the single 1X or single 2X sources. Crayfish altered orientation strategies when presented with different spatial arrangements of food cues. In particular, the temporal aspects of the orientation pattern were most altered by the differences in odor presentations. Crayfish responded with faster walking speeds as a function of distance to the odor source and exhibited more consistent turning angles. This correlates with temporal changes in odor structure, and indicates that the temporal pattern of odor stimulation may be driving the temporal pattern of behavior.

Animals↗
PubMed2004

Characteristics of the behavior and stress-reactivity of the hypophyseal-adrenal system in prenatally stressed rats.

The effects of daily 1-h immobilization of female rats from days 15 to 18 of pregnancy on the levels of anxiety, orientational-investigative activity in an open field test, and the dynamics of the stress response of the hypophyseal-adrenal system were studied in the male and female adult offspring of these rats. Maternal stress was found to induce significant reductions in the level of orientational-investigative activity of females in the stage of diestrus, and to increase anxiety as measured in an elevated cross maze. Prenatally stressed males, conversely, had decreased levels of anxiety, and behavior in the open field test was virtually unaltered. As a result, prenatally stressed rats showed smoothing out of the intergender differences in these forms of behavior, seen in control animals in normal conditions. Prenatal stress had a significant influence on the dynamics of the stress response of the hypophyseal-adrenal system in males and females; males showed impairment of the feedback control of this system in conditions of stress activation, while females showed significant increases in the maximum level of adrenal corticosterone secretion into the blood in response to immobilization lasting 20 min. These data provide evidence that maternal stress has significant influences on behavior and the stress response in both male and female rats.

Animals↗
PubMed1995

Activity and mood temperament as predictors of adolescent substance use: test of a self-regulation mediational model.

The authors tested a mediational model of temperament dimensions and substance use with a sample of 1,826 urban adolescents, M age 12.3 years. Five scales from the Revised Dimensions of Temperament Survey (DOTS-R) were administered together with measures of substance (tobacco, alcohol, marijuana) use and measures of related variables derived from a self-regulation model. Unique contributions to substance use were found for DOTS-R dimensions of high activity level (positively related) and positive mood (inversely related). High activity level and low positive mood were also related to lower levels of parental support. Analyses, including multiple regression and structural modeling, identified generalized self-control, maladaptive coping (anger and helplessness), novelty seeking, and affiliation with peer substance users as mediating the effect of temperament on substance use, with control for effects of parental support. Parental support was inversely related to substance use through several pathways. Implications for the theory of vulnerability are discussed.

Adaptation, Psychological↗
PubMed1999

Can memory requirements account for species' differences in invisible displacement tasks?

We tested the hypothesis that poor performance on the Piagetian invisible displacement task is related to increased memory requirements. Rhesus monkeys and orangutans received 3 types of problems (invisible, visible, and no transfer problems) each containing a number of steps equivalent to that of standard invisible displacements. If failure to solve invisible displacements was due to increased memory requirements, then the primates should perform at chance level on all 3 problems. However, rhesus monkeys solved visible and no transfer problems, but not invisible transfer problems. Half of the orangutans solved all 3 transfer problems, although their performance on invisible transfer problems was lower than that on the other problems. A subsequent cuing phase led to improved performance, and a few monkeys solved invisible transfer problems.

Animals↗
PubMed1993

Development of combinatorial manipulation in infant baboons (Papio cynocephalus anubis).

Infant baboons (Papio cynocephalus anubis) housed in individual cages combined objects and used tools in play and food acquisition. The baboons first combined objects at age 2 months, placed objects inside a container at age 4 months, and repeatedly used paper towels as sponges at age 6 months. The results of this investigation demonstrate that infant baboons develop extensive manipulative propensities during the first postnatal semester. These data are consistent with hypotheses that (a) creative recombination facilitates the acquisition of novel behavior patterns and (b) the development of combinatorial manipulation in baboons parallels the development of analogous abilities in human infants.

Animals↗
PubMed1994

Video-task assessment of stimulus novelty effects on hemispheric lateralization in baboons (Papio papio).

In a video matching-to-sample task, we examined the effects of stimulus novelty on hemispheric specialization in 6 baboons (Papio papio). After familiarization with a set of 8 composite stimuli, baboons were tested with either familiar stimuli paired in a novel way, novel stimuli composed of familiar elements, or novel stimuli differing in structure from the previous stimuli. Analyses focused on visual field differences between initial and later trials in each condition. The findings reflected shorter left than right visual half-field response times for initial but not for terminal trials. With regard to accuracy, scores were smaller for the initial trials than for the later ones, but there was no significant difference between left and right visual half-fields. Overall, this study suggests that hemispheric lateralization changes with practice and that the right hemisphere of the baboon plays a critical role in the processing of novelty.

Animals↗