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At least 991 records · Page 55Linked to original sources

PubMed1986

The stress of a novel environment reduces formalin pain: possible role of serotonin.

Compared to rats that were given three daily sessions of habituation to a laboratory environment, non-habituated rats were behaviourally less reactive when pain was produced by 0.05 ml of 2.5% formalin injected s.c. in one hindpaw. This behavioural analgesia was equivalent to that produced by approximately 2.0 mg/kg morphine and was interpreted as analgesia induced by the stress of exposure to a novel environment. Methysergide (10 mg/kg) or 1-valine (200 mg/kg) alone, or combined with naloxone (0.1 or 2.0 mg/kg), reversed the effect of exposure to a novel environment. Naloxone itself had no significant effect. In habituated rats 1-valine reduced the response to formalin-induced pain whereas methysergide combined with naloxone increased it. It is concluded that analgesia induced by the stress of exposure to a novel environment depends on serotonin.

Animals↗

PubMed1995

Models for the effects of individual size and spatial scale on competition between species in heterogeneous environments.

A spatially explicit model for competition with dispersal in a heterogeneous environment is used to study the effects of individual size and the spatial scale of the environment on the competitive interactions between species. The model is a Lotka-Volterra competition system with diffusion and with spatial variation in some coefficients. The coefficients in the model are taken to reflect a situation where the larger competitor typically disperses farther in unit time than the smaller and reproduces less rapidly, but has an advantage in contests or other forms of interference competition. The environment is assumed to be closed, i.e., it is assumed that individuals do not leave through the boundary. The environment is generally assumed to consist of a patch of favorable habitat surrounded by less favorable regions. The effects of spatial scale are studied by examining how the predictions of the model change as the size of the favorable patch is varied. The predictions turn out to be in qualitative agreement with the results of some empirical studies.

Ecosystem↗

PubMed1985

Depression of rat feeding in familiar and novel environment by sulfated and nonsulfated cholecystokinin octapeptide.

The effects of cholecystokinin octapeptide sulfate ester (CCK-8-SE) and nonsulfated cholecystokinin octapeptide (CCK-8-NS) were tested on feeding by rats in familiar and novel environment. In a familiar environment only intraperitoneally (IP) administered CCK-8-SE (0.8-24 nmole/kg) could inhibit 30 min food intake of 24 hr food-deprived rats, while the same doses of CCK-8-NS IP and both octapeptides (0.8-8000 pmole/rat) intracerebroventricularly (ICV) were totally ineffective. The effects of CCK-8-SE and CCK-8-NS on feeding were also tested in a novel environment, i.e., in an open field. The parameters of exploratory activity and food intake of 24-hr food-deprived rats were recorded simultaneously during a 15-min session. After IP injection, CCK-8-SE dose-dependently depressed the food intake, and the higher doses (8.0 or 24 nmole/kg) also decreased the open field parameters, including number of approaches to food. In the novel environment, 8.0 or 24 nmole/kg IP injected CCK-8-NS also depressed the food intake, whereas the incidence of grooming was enhanced after 8.0 nmole/kg CCK-8-NS. The most effective doses of both octapeptides increased the latency to first bite. For the open field test ICV treatment was also carried out with 8, 80 or 800 pmole doses of the octapeptides, and after 80 pmole CCK-8-SE ICV the food intake was decreased, and after 80 or 800 pmole CCK-8-SE and 800 pmole CCK-8-NS the food intake/approach parameter was depressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

The effects of bilateral and unilateral vibrissotomy on behavior within aquatic and terrestrial environments.

Introducing an untreated rat to a novel environment typically results in thigmotaxis or wall-seeking behavior and the unilateral removal of the vibrissae induces an asymmetry in thigmotaxis. The present study investigated the effects of bilateral and unilateral removal of the vibrissae (vibrissotomy) upon the rat exhibiting thigmotaxis within aquatic and terrestrial environments. Unilateral vibrissotomy resulted in directional thigmotaxis asymmetry toward the intact vibrissae side within both environments. Within the aquatic environment, the unilateral vibrissotomy group swam a significantly longer distance than the other two groups. The data are discussed in terms of activation and sensory information.

Animals↗

PubMed1976

The state of the environment 1976.

One of the main points made recently by the Executive Director of the United Nations Environment Programme, in describing the state of the current environment in the world, was that the present nuclear arms race is a potential environmental hazard, larger than any other created. It was pointed out that the nuclear stockpiles of the major powers in 1974, amounting to 30,000 megatons, were two million times the destructive capacity of the Hiroshima bomb. The State of the Environment report continues to examine also the conventional arms race, pointing out that the combined military expenditure by developing countries has increased by the rate of ten per cent a year since 1960, taking scarce foreign exchange to build up arsenals, rather than developing the environment of these countries or alleviating the poverty of the people living in these countries. Other major points described in the report: 1. In terms of pollution, even a relatively small change in one of the controlling factors of the world climate would have serious consequences for mankind, hampering the increase in world food. 2. It is still not known what the earth's real "carrying capacity" is, and all that is known is that the earth can meet only the basic needs of a finite number of people. 3. Hunger is the main problem in the world today and can only be solved through wise development and the doubling of global food production. 4. Almost half of the 7,000 million people expected to be alive in the year 2,000 will live in towns and cities, more than 64 per cent of these people in developing countries. 5. On a positive note, there is a much greater awareness on the part of the people of the world, a greater reduction of pollution in many parts of the world, and a co-operation among governments-and a marked progress in the field of international environmental law. The report concludes by warning the world that it must consume less resources less wastefully and that without political will science can do nothing. The essence of the environmental challenge, therefore, is political rather than technical.

Air Pollution↗

PubMed1985

An examination of heroin conditioning in preferred and nonpreferred environments and in differentially housed mature and immature rats.

The study addressed two issues. First, we examined the effectiveness of heroin as a conditioning agent in a preferred environment using a place preference paradigm. Four daily injections of 80 micrograms/kg (SC) of heroin HCl were paired with environments that rats initially found to be either preferred or non-preferred. In subsequent tests, only those that had experienced the drug effects in the non-preferred environment increased the percentage of time spent in that environment. Rats conditioned in the test chamber that was initially preferred failed to increase the amount of time spent in that chamber post-conditioning. These results suggest that the conditioned place preference paradigm does not simply assess the rewarding consequence of heroin injections. We also examined the effects of grouped and isolation housing conditions on the heroin-produced conditioned place preference. Rats were housed under these conditions either immediately post weaning or at 120 days of age. There was a difference between the magnitude of the place preference produced by 20 micrograms/kg heroin in the isolated but not in the group housed rats. When isolated at weaning the rats were less sensitive to the drug than were rats isolated at maturity. These data are discussed with particular reference to the development of the endogenous opioid system.

Aging↗

PubMed1993

Novel environment and cat odor change GABA and 5-HT release and uptake in the rat.

In hippocampal and cortical slices taken from rats moved in their home cages to a novel environment for 5 min, there were decreases in basal and K(+)-evoked [14C]GABA release and an increased [14C]GABA uptake compared with slices taken from rats remaining undisturbed in the animal house. The changes in 5-hydroxytryptamine (5-HT) release and uptake in response to a novel environment were markedly time dependent. In rats killed immediately after the 5-min exposure, there was decreased hippocampal [3H]5-HT uptake and higher hippocampal basal release, whereas in rats killed 30 min later there was increased [3H]5-HT uptake and lower basal release in both hippocampal and cortical slices. Rats exposed to cat odor in the novel environment showed increased release and decreased uptake of GABA in both brain areas compared with the group exposed to a neutral odor in the same novel environment, and these differences between the two odor groups were found both immediately and 30 min after the odor exposure. In contrast, only one measure of 5-HT function differed between the neutral and cat odor groups, with the latter showing increased cortical [3H]5-HT uptake 30 min after odor exposure.

Animals↗

PubMed1982

Behavioural comparisons between individually- and group-housed male rats: effects of novel environments and diurnal rhythm.

Individually-housed rats, when compared with group-housed controls, have been previously shown to be hyper-reactive when exposed to an openfield at the beginning of the dark-phase; this was not due to elevated spontaneous activity. In the present experiments locomotor and rearing activities were determined immediately after exposing animals to a novel environment, and after 6 and 24 h of habituation to the test-environment. Additionally, after 24 h of adaptation, animals' responses towards a modification of the test-environment were examined. Four parallel experiments were carried out, each starting at a different time in the light/dark cycle. Individually-housed rats were hyper-reactive in novel environments and showed a slower habituation at all time points tested. Part of behavioural parameters show clearcut day/night variations, but differences between individually- and group-housed rats do not seem to be influenced by the time of day.

Animals↗

PubMed1989

Early martian environments: the Antarctic and other terrestrial analogs.

The comparability of the early environments of Mars and Earth, and the biological evolution which occurred on early earth, motivates serious consideration of the possibility of an early martian biota. Environments which could have contained this early martian life and which may presently contain evidence of this former life include aquatic, ice, soil, and rock habitats. Several analogs of these potential early martian environments, which can provide useful information in searching for extinct life on Mars, are currently available for study on Earth. These terrestrial analogs include the perennially ice-covered lakes and sandstone rocks in the Polar Deserts of Antarctica, surface of snowfields and glaciers, desert soils, geothermal springs, and deep subsurface environments.

Antarctic Regions↗

PubMed1984

Differentiation--a consequence of idiotype-environment interaction.

The present paper deals with a model of idiotype-environment interaction and its application to a tissue culture experiment with birch (Betula pendula ROTH.). The data of the experiment are characterized with respect to the physiological reactions and are discussed in the light of the model. The main results of the paper are: With respect to the environmental action one has to discriminate between the environment inside and outside the cell (external and internal environment). The environmental influences cause a differential gene activity which lead to transient differentiation states and to final states of differentiatedness. During mitosis two types of information transmission take place: transmission of genetic material (the "blueprint") and transmission of the milieu (the "experience" of previous events). They together give rise to differentiation. The data of the experiment show that differentiation is no one-way street: Because of the transmitted milieu it is sometimes easier to regain an earlier differentiation state than to reach a new one. Only the interaction of idiotype (sum of genetic information) and the milieu state (internal environment) causes parallel as well as divergent development of cell lines. The model is also used to reinterpret some selected papers in the literature.

Cell Differentiation↗

PubMed1985

Environmental stressors and chronic low back pain: life events, family and work environment.

Stressors in the family and job environments have been proposed to play a role in the modulation of pain, yet direct empirical support for such a role is limited. The present study investigated the relationship between general stress, family and work environments (perceived social climate), psychological distress (anxiety, depression), and pain experience (sensory, affective, evaluative) in 33 ambulatory chronic low back pain (CLBP) subjects and 35 healthy controls matched for age, sex, socioeconomic status (SES), weight, and height. Results indicated that environmental stressors/social climate measures, including family conflict, family control, and general stress (Social Readjustment Rating Scale), were greater in the CLBP group. Distress measures were also higher in the CLBP group. Characteristics of the family and work environments were found to be more predictive of the affective and evaluative dimensions of pain. Increased family conflict was associated with increased distress and increased pain, while increased family independence was correlated with less distress and increased pain. Less peer cohesion, less physical comfort, and less job clarity were correlated with increased pain, but not distress. Work pressure was associated with decreased depression and less pain. These findings suggested the presence of both stress and operant mechanisms in the modulation of pain in the family, while operant and distraction mechanisms appear to characterize the relationship among work environment factors and pain.

Adaptation, Psychological↗

PubMed1988

Family environment of adolescents and coping in the hospital.

The purpose of this study was to test the relationship between social environment and the activity of the HPA axis in adolescents. Ten elective admissions to Children's Hospital at Stanford were assessed by standard psychiatric interview. Five fulfilled criteria for a DSM-III diagnosis, five others did not. The groups were comparable in age, height, weight, SES, and number of previous hospitalizations. All subjects and their families completed the Family Environment Scale. All subjects had plasma cortisol concentrations determined on days 1, 3, and 5 of hospitalization and at the time of discharge. Samples were drawn under standardized conditions, after a brief interview during which potentially stressful events of the day were discussed. Results revealed that the five individuals with poor coping skills, as defined by the presence of a DSM-III diagnosis, had significantly higher peak concentrations of plasma cortisol, than the five psychiatrically normal subjects. Peak cortisol elevations occurred upon discharge from the hospital. Family environment in the two groups differed significantly on the dimensions of cohesion, conflict, control, and incongruence of perception of the environment among family members themselves. The findings support the hypothesis that social environmental characteristics are associated with psychiatric and physiological measures of coping.

Adaptation, Psychological↗

PubMed1992

The impact of a staff support group on the work environment of a specialty unit.

The purpose of this study was to evaluate the impact of a staff support group led by a psychiatric liaison nurse on the work environment of a specialty unit. Before and at the completion of a series of 12 group meetings, participants completed two forms (real and ideal) of the Work Environment Scale (WES) that elicited their perceptions of the unit's work environment and their preferences for an ideal work environment. Initial findings were used to guide the content and process of the group intervention. Subjects real and ideal scores, as well as real-ideal discrepancies before and after intervention were compared using t tests. Statistically significant changes were found on the dimensions of clarity and control. Clinical observations showed a decrease in staff conflict and improvement in interpersonal communication.

Adaptation, Psychological↗

PubMedDate not supplied

Baccalaureate educator use of environment-based strategies to teach diagnostic patterns.

Baccalaureate nurse educators reported that their use of 10 environment-based strategies in the classroom or clinical setting may foster recognition of diagnostic patterns likely to be encountered in clinical practice. Environment-based strategies are verbal or print materials that draw attention to a particular aspect of what is being taught and that draw attention to important information. A national sample of 255 full-time baccalaureate educators (56 per cent return rate) from 28 randomly selected programs completed a questionnaire. The reliability estimate related to the 10 items was 0.70. Most respondents reported use of all 10 environment-based strategies with a minimum reported use of 60 per cent for each strategy on at least a "sometimes" basis. The most frequently reported use of a strategy on a "greater than sometimes" basis was the transparency (75 per cent). Color and print differences were the most infrequently used at 40 per cent and 37 per cent, respectively. The results of this study show that faculty, either consciously or unconsciously, use the environment-based strategies to facilitate student selection of key diagnostic indicators. Increasing educators' awareness of such benefits to students may stimulate further research in this area. Methods to help students decipher significant health status indicators from associated ones are clearly needed so that timely intervention can be used to prevent harm to patients.

Attention↗

PubMed2006

The Irvine-Minnesota inventory to measure built environments: development.

BACKGROUND: Researchers and policymakers increasingly identify active living-including walking and bicycling for travel and recreation-as a potential strategy to increase rates of physical activity in the United States. Understanding the impact of the built environment on physical activity levels requires reliable methods to measure potentially relevant built environment features. This paper presents an audit tool-the Irvine Minnesota Inventory-that was designed to measure a wide range of built environment features that are potentially linked to active living, especially walking. METHODS: The inventory was created through a literature review, focus group interviews, a panel of experts, and field testing in 27 settings. The inventory was developed in 2003-2004. RESULTS: The Irvine Minnesota Inventory includes 162 items, organized into four domains: accessibility (62 items), pleasurability (56 items), perceived safety from traffic (31 items), and perceived safety from crime (15 items). (Some items are in multiple domains.) The inventory includes both a paper version and a version in Microsoft Access, to allow data to be input directly into the computer. CONCLUSIONS: Limitations of methods used to develop the inventory are discussed. Strategies are offered for using the Irvine Minnesota Inventory to systematically and reliably measure characteristics of the built environment that are potentially linked to active living.

Bicycling↗

PubMed2004

Navigation in virtual environment by the macaque monkey.

To determine whether monkeys can navigate a virtual environment, and whether they can represent a virtual environment in their brain, we trained two macaque monkeys to perform a navigation task in a virtual building and conducted behavioral analyses. After learning the task from the first starting point, they were trained to perform the navigation task from a second starting point which is already familiar to them during the first training session. The second training was completed faster than the first one. Furthermore, we found that the time required for a free-way-finding test from a novel starting point was shortened after the second training. These results suggest that monkeys can navigate a virtual environment and can construct a flexible representation of a virtual environment in their brain.

Animals↗

PubMed2004

Abilities in tactile discrimination of textures in adult rats exposed to enriched or impoverished environments.

In previous studies, we have shown that housing in enriched environment for about 3 months after weaning improved the topographic organization and decreased the size of the receptive fields (RFs) located on the glabrous skin surfaces in the forepaw maps of the primary somatosensory cortex (SI) in rats [Exp. Brain Res. 121 (1998) 191]. In contrast, housing in impoverished environment induced a degradation of the SI forepaw representation, characterized by topographic disruptions, a reduction of the cutaneous forepaw area and an enlargement of the glabrous RFs [Exp. Brain Res. 129 (1999) 518]. Based on these two studies, we postulated that these representational alterations could underlie changes in haptic perception. Therefore, the present study was aimed at determining the influence of housing conditions on the rat's abilities in tactile texture discrimination. After a 2-month exposure to enriched or impoverished environments, rats were trained to perform a discrimination task during locomotion on floorboards of different roughness. At the end of every daily behavioral session, rats were replaced in their respective housing environment. Rats had to discriminate homogeneous (low roughness) from heterogeneous floorboards (combination of two different roughness levels). To determine the maximum performance in texture discrimination, the roughness contrast of the heterogeneous texture was gradually reduced, so that homogeneous and heterogeneous floorboards became harder to differentiate. We found that the enriched rats learned the first steps of the behavioral task faster than the impoverished rats, whereas both groups exhibited similar performances in texture discrimination. An individual "predilection" for either homogeneous or heterogeneous floorboards, presumably reflecting a behavioral strategy, seemed to account for the absence of differences in haptic discrimination between groups. The sensory experience depending on the rewarded texture discrimination task seems to have a greater influence on individual texture discrimination abilities than the sensorimotor experience related to housing conditions.

Analysis of Variance↗

PubMed2006

Enriched environment treatment counteracts enhanced addictive and depressive-like behavior induced by prenatal chronic stress.

Prenatal stress can cause many long-term behavior changes in offspring, but whether prenatal stress can alter addictive behavior in offspring and postnatal enriched environment treatment (EE) can restore these changes are unknown. We reported here that prenatal chronic stress (10 unpredictable, 1 s, 0.8 mA foot-shocks per day during gestational days 13-19) enhanced morphine-induced (10 mg/kg, s.c., per day, 6 consecutive days) place preference. Moreover, prenatal chronic stress caused higher depressive-like behavior in forced swimming test in adult offspring. However, enriched environment housing treatment on postnatal days 22-52 counteracted both the abnormal behaviors alterations. This work observed a phenomenon that might contribute to the understanding of clinically important interactions among addiction, prenatal stress and enriched environment treatment. Postnatal enriched environment treatment might be an important therapeutic intervention in preventing the prenatal stress-induced addictive disorders.

Analysis of Variance↗