PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Exploratory Behavior”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,729 records · Page 96Linked to original sources
PubMed2004

Maternal behavior regulates benzodiazepine/GABAA receptor subunit expression in brain regions associated with fear in BALB/c and C57BL/6 mice.

Inbred strains of mice, such as BALB/cByJ and C57BL/6ByJ, have been used repeatedly to study genotype-phenotype relations. These strains differ on behavioral measures of fear. In novel environments, for example, BALB/c mice are substantially more neophobic than C57BL/6 animals. The benzodiazepine (BZ)/GABAA receptor system has been proposed as a regulator of behavioral responses to stress, and BALB/c and C57BL/6 mice differ in BZ/GABAA receptor binding. In the present study, we found increased BZ receptor levels in C57BL/6 mice in the central and basolateral nuclei of the amygdala as well as the locus coeruleus using either flunitrazepam (nonselective) or zolpidem (alpha1 subtype selective) as radioligands. Differences in receptor binding were most pronounced in the amygdala and locus coeruleus using [3H]zolpidem. C57BL/6 mice showed increased alpha1 mRNA levels in the locus coeuruleus compared to BALB/c mice. In addition, gamma2 mRNA expression in BALB/c mice was decreased in the central nucleus of the amygdala to levels that were 2-2.5-fold lower than those of C57BL/6 mice. The results of an adoption study revealed that the biological offspring of C57BL/6 mothers fostered after birth to BALB/c dams showed decreased levels of gamma2 mRNA expression in the central nucleus of the amygdala in comparison to peers fostered to other C57BL/6 mothers (the reverse was found for the biological offspring of BALB/c mothers). In a step-down exploration paradigm, BALB/cByJ mice crossfostered onto a C57BL/6ByJ dam expressed reduced anxiety responses. However, among C57BL/6ByJ mice, the relatively low levels of anxiety ordinarily evident were not increased when mice of this strain were reared by a BALB/cByJ dam. These preliminary findings suggest that the strain differences in the BZ/GABAA receptor system occur, at least in part, as a function of parental care. Such findings may reflect a mammalian example of an indirect genetic effect mediated by maternal care.

Adoption↗
PubMed2001

Dorsal hippocampal lesions impair appetitive classical conditioning to localized cues.

Three experiments examined appetitive classical conditioning in rats with small electrolytic lesions of the dorsal hippocampus. In all the experiments, the reinforcer was food delivery and the conditioned response (CR) entry to the food tray; the three experiments differed in the nature of the conditioned stimulus (CS). When this was a small light located inside the food tray, conditioning was impaired in lesioned animals, but when the CS was a general increase in illumination, they learned at the same rate as controls. With a white noise as the CS, learning was significantly faster in lesioned subjects. These data demonstrate that lesions of the dorsal hippocampus can produce impairments in appetitive delay conditioning, but only with certain types of CS. It is suggested that deficits are found with CSs that are localized in space.

Animals↗
PubMed2004

Cooperation between Drosophila flies in searching behavior.

In Drosophila melanogaster food search behaviour, groups of flies swarm around and aggregate on patches of food. We wondered whether flies explore their environment in a cooperative way as interactions between individual flies within a population might influence the flies' ability to locate food sources. We have shown that the food search behavior in the fruit fly Drosophila is a two-step process. Firstly, 'primer' flies search the environment and randomly land on different food patches. Secondly, the remaining group of flies move to the most favorable food source and aggregate there. We call this a 'search-aggregation' cycle. Our data demonstrate that flies do not individually assess all available food resources. Rather, social interactions between flies appear to affect their choice of a specific food patch. A genetic analysis of this 'search-aggregation' behavior shows that flies carrying mutations in specific genes (for example, the dunce (dnc) gene which codes for a phosphodiesterase) were defective in this search-aggregation behavior when compared to normal flies. Future investigations of the neuronal signaling involved in this behavior will help us to understand the complexities of this aspect of Drosophila social behaviour.

Animals↗
PubMed2003

The high-affinity non-peptide CRH1 receptor antagonist R121919 attenuates stress-induced alterations in plasma oxytocin, prolactin, and testosterone secretion in rats.

Evidence from basic and clinical research suggests that hyperactivity of central corticotropin-releasing hormone (CRH) circuits contributes to causality and course of affective disorders. Therefore, CRH receptor antagonists have attracted attention as potential therapeutics. We could previously show that the novel high-affinity non-peptide CRH 1 receptor antagonist R121919 significantly inhibits stress-induced corticotropin release and displays anxiolytic effects in rats selectively bred for high anxiety-related behavior. These animals are characterized by their innate hyper-reactivity of the hypothalamic-pituitary-adrenocortical system linked to an increased emotionality and therefore are suitable for the evaluation of CRH 1 receptor antagonists. Here we show that in addition to its effects on anxiety-related behavior and corticotropin secretion, R121919 attenuates the stress-induced release of corticosterone, prolactin, and oxytocin. Moreover, the decrease in plasma testosterone following exposure to stress is abolished by R121919. Our data indicate that antagonism of CRH 1 receptors may prevent stress-associated endocrine alterations.

Adrenocorticotropic Hormone↗
PubMed2005

Genotype-environment interactions in mouse behavior: a way out of the problem.

In behavior genetics, behavioral patterns of mouse genotypes, such as inbred strains, crosses, and knockouts, are characterized and compared to associate them with particular gene loci. Such genotype differences, however, are usually established in single-laboratory experiments, and questions have been raised regarding the replicability of the results in other laboratories. A recent multilaboratory experiment found significant laboratory effects and genotype x laboratory interactions even after rigorous standardization, raising the concern that results are idiosyncratic to a particular laboratory. This finding may be regarded by some critics as a serious shortcoming in behavior genetics. A different strategy is offered here: (i) recognize that even after investing much effort in identifying and eliminating causes for laboratory differences, genotype x laboratory interaction is an unavoidable fact of life. (ii) Incorporate this understanding into the statistical analysis of multilaboratory experiments using the mixed model. Such a statistical approach sets a higher benchmark for finding significant genotype differences. (iii) Develop behavioral assays and endpoints that are able to discriminate genetic differences even over the background of the interaction. (iv) Use the publicly available multilaboratory results in single-laboratory experiments. We use software-based strategy for exploring exploration (see) to analyze the open-field behavior in eight genotypes across three laboratories. Our results demonstrate that replicable behavioral measures can be practically established. Even though we address the replicability problem in behavioral genetics, our strategy is also applicable in other areas where concern about replicability has been raised.

Analysis of Variance↗
PubMed1984

Curiosity and demographic factors as determinants of children's probability-learning strategies.

Children's curiosity, gender, activity level, and socioeconomic status (SES) were related to their performance on a partially reinforced discrimination-learning task. The 38 boys and 37 girls were in the first grade and were all white. Three factors of curiosity (manipulatory, conceptual, and about the complex) were assessed. Performance on the learning task was scored for the number of correct responses (maximizing) and for the frequency of three-step sequences reflecting variability, systematic patterning, and perseveration. In general, the three curiosity factors related negatively to maximizing and perseveration and positively to variability. (The same effects were found for activity level.) Systematic patterning related positively to one curiosity type and negatively to another. Girls used less maximizing and more systematic patterning than boys. The response choices of girls were affected more by differences in conceptual curiosity and those of boys by differences in curiosity about the complex. Activity level was unrelated to gender but differed with SES. The findings demonstrate the role of different curiosity factors in shaping response sequences and suggest some reasons for children's choice of probability-learning strategies.

Child↗
PubMedDate not supplied

Perceived work environment and cognitive style.

Differences in perceived work environment are examined by age, gender, and occupation type, along with whether cognitive style predicts perceived work environment. The sample consists of 2185 men and women ranging in age from 21 to 93 years. Perceived work environment was measured using Moos's Work Environment Scale (WES) for the subscales of Autonomy, Control, and Innovation. The Test of Behavioral Rigidity (TBR) was used to measure cognitive style. Findings indicate significant mean level differences in perceived work environment based on gender, age, and occupation type. Hierarchical regression analyses indicated that perceived work environment predicted concurrent cognitive style beyond demographic variables.

Adult↗
PubMed2003

Prolonged treatment with L-lysine and L-arginine reduces stress-induced anxiety in an elevated plus maze.

The aim of this study was to investigate whether a chronic pretreatment with a combination of L-lysine (Lys) and L-arginine (Arg) reduces anxiogenic effects of acute stress in rats. Male rats were orally infused with a distilled water solution of L-glutamine (200 mg/kg), Lys (200 mg/kg), or a combination of Lys (200 mg/kg) plus Arg (200 mg/kg) for four consecutive days (twice daily) and subjected to restraint stress on the fifth day. Immediately thereafter, rats were placed on an elevated plus maze (EPM) and their behavior was evaluated for 10 min. Lys and Arg significantly increased exploration time rats spent on open arms of the EPM, as compared to L-glutamine controls. In addition, the combination of Lys and Arg partly, but significantly, decreased stress-enhanced plasma corticosterone measured at the end of behavioral testing. Data suggest that a treatment with a solution of Lys and Arg reduces anxiety in stressed rats.

Animals↗
PubMed2005

Developmental lead exposure induces depressive-like behavior in female rats.

The involvement of neurotoxicants in the etiology of emotional pathologies is becoming an issue in neurotoxicology. Lead (Pb) exposure during childhood has been associated with increased impulsivity, aggressivity, and delinquency. Considering the paucity of experimental studies investigating the involvement of developmental Pb exposure in emotional disorders, our objective was to investigate whether Pb exposure during pregnancy and/or lactation could be related to depressive symptoms in adult male and female rats. Wistar dams received 10 mg of Pb, as Pb acetate, or 13.4 mg of Na acetate, by gavage, daily, during pregnancy and lactation. By cross-fostering at the time of birth, pups were either exposed to Pb or Na acetate during pregnancy only, lactation only, or during both pregnancy and lactation. At 70 days of age, animals were submitted to the open-field test followed by the forced swimming test. Pb levels were measured in the blood of dams (weaning) and pups (after behavioral evaluation). The results demonstrated that exposure to Pb during both pregnancy and lactation induced, in males, an increased emotionality state detected in the open-field test, and in females, depressive-like behavior detected in the forced swimming test. These alterations were observed at residual blood Pb levels (i.e., around 5 microg/dL).

Administration, Oral↗
PubMed2001

Burrowing into prion disease.

Mice received intra-hippocampal injections of scrapie-infected brain homogenate. Open field activity increased from around week 12 post-injection. Concomitantly the tendency to displace food from a tube inside the home cage decreased. The food was generally dug out with the feet, rather than carried by mouth, so its displacement was called burrowing. Food restriction was unnecessary for this burrowing to occur. Only later, around 18 weeks, did more general motor impairments develop. As burrowing in scrapie-infected mice decreased when open field activity increased, and preceded later motor impairments, it was not due to motor dysfunction. Burrowing is a simple, sensitive, objective, ethological measure, sensitive to preclinical prion disease. Other potential applications are in transgenic and knockout mice, models of ageing and Alzheimer's disease, and pharmacology, particularly neuroleptics.

Animals↗
PubMed2005

Altered anxiety and depression-related behaviour in mice lacking GABAB(2) receptor subunits.

Metabotropic GABAB receptors predominantly function as heterodimers of GABAB(1) and GABAB(2) subunits, but GABAB(1) can also form functional receptors in the absence of GABAB(2). Mice lacking the GABAB(1) subunit have altered behavioural responses in tests for anxiety and depression. In these studies, we investigated anxiety and depression in GABAB(2)-deficient mice. We compared the effects directly with that of genetic deletion of the GABAB(1) receptor subunit. Both GABAB(1) and GABAB(2)-deficient mice were found to be more anxious than wild type in the light-dark box paradigm. In contrast, these mice exhibited an antidepressant-like behaviour in the forced swim test. Taken together, these data suggest that heterodimeric GABAB(1,2) receptors are required for the normal regulation of emotional behaviour.

Animals↗