SEARCH · PubMed Health

Results for “SOCIAL ISOLATION”

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 145 records · Page 8Linked to original sources

PubMed1990

Thermal correlates of tonic immobility and social isolation in chickens.

Previous research has shown that core temperature in chickens drops following the induction of tonic immobility (TI), while hyperthermic trends emerge shortly after response termination. Other research has shown that birds placed in social isolation also become hyperthermic. Since testing for TI is usually carried out while animals are isolated, there is a question as to whether the hyperthermic reaction after the termination of TI has any relation to the episode of TI itself as opposed to being due to the effects of social isolation per se. The present series of studies found that although social isolation did produce significantly longer durations of TI and that the core temperature of isolated birds was affected, when core temperatures were independently raised or lowered, no significant differences were found in TI durations relative to controls. Additionally, in contrast to core temperature changes, shank temperature showed the opposite effect, while another peripheral temperature measure, wing temperature, remained stable.

Aging↗

PubMed1991

Central administration of oxytocin modulates the infant rat's response to social isolation.

Several lines of evidence suggest that oxytocin modulates the formation and maintenance of social bonds. In the current experiments we investigated the influence of centrally and peripherally administered oxytocin on the behavior of 6-8 day old rat pups during brief periods of social isolation. Ultrasonic vocalizations emitted by isolated pups were decreased following i.c.v. administration of oxytocin, at doses (500, 1000 ng) which did not affect motor activity. S.c. administered oxytocin (1, 10 micrograms) produced a biphasic change in ultrasonic vocalizations, depending on dose. Central administration of the oxytocin antagonist (d(CH2)5[Tyr(Me)2, Thr4, Tyr-NH2(9)]OVT) (OTA, 500 ng) did not measurably affect pup behavior by itself but did block the decrease in calls following central but not peripheral administration of oxytocin. These data demonstrate that oxytocin via its central receptor can regulate the response to social isolation.

Angiotensin Receptor Antagonists↗

PubMed2001

Social isolation stress impairs the resistance of mice to experimental liver metastasis of murine colon 26-L5 carcinoma cells.

Our previous study has demonstrated that the exposure of male BALB/c mice to social isolation stress caused a suppressed immune response and enhanced liver metastasis of colon 26-L5 carcinoma cells. To more precisely understand the influence of psychosocial factors on the metastatic process, here we have investigated the effect of social isolation stress on the vulnerability of the host to develop liver metastasis of colon 26-L5 cells, including the time span and incidence of metastatic formation, survival time and chemotherapy response. Isolation stress decreased the time period required for the metastasis formation relative to that in controls. On day 7 after the tumor injection, the 75% incidence of tumor metastasis in the stressed mice was 5 times the 15% incidence in the unstressed mice. When exposed to the challenge of lower cell numbers (0.025, 0.05, 0.1 x 10(4)/mouse) of colon 26-L5 cells, mice subjected to isolation stress developed an elevated incidence of metastasis (33.3, 66.6, and 100%, respectively) as compared with the controls (0, 33.3 and 50%, respectively). The survival time following the tumor inoculation was also shorter in the stressed mice (21.83 +/- 1.59d) than in the control mice (24.08 +/- 1.68 d). Furthermore, the response of liver metastasis to chemotherapy consisting of 2 mg/kg cisplatin (CDDP) was worse in the stressed mice than that in unstressed mice. These findings suggested that social isolation stress could significantly impair the resistance of mice to the development of metastasis.

Animals↗

PubMed2005

Migrant status, age, gender and social isolation in very late-onset schizophrenia-like psychosis.

BACKGROUND: Data from two retrospective first contact studies suggest that the risk of developing very-late onset schizophrenia-like psychosis (SLP) may be raised in older migrant than British-born populations resident in the UK. OBJECTIVE: To investigate whether the relative excess of SLP observed amongst younger and male migrants in the above studies might have been explained by differences in the age-gender structures of migrant and British-born denominator populations. A secondary aim was to examine the associations of migrant group status and gender with markers of social isolation. METHOD: Eighty-six new referrals of SLP to the Mile End (1997-2003) and Maudsley (1995-2000) hospitals were identified from two retrospective case note studies. Local census data were used to estimate the denominator populations and to calculate rate ratios for migrant and British-born cases of SLP. Case notes were re-examined, to assess markers of social isolation in migrant and British-born patients. RESULTS: Migrant patients were more likely to be male (odds ratio = 4.8; CI(odds) = 1.8-13.2) than British-born patients. The ratio of first contact rates for migrant compared to British-born populations were highest amongst men. There was a lower mean age of onset of SLP in migrant than British-born patients (t = 4.30, 95% CI = 3.78-10.27), which was largely explained by a higher mean age of illness onset in British-born women. There were no differences between migrant and British-born patients with respect to markers of social isolation. Male patients were more likely to have never married than women (odds ratio = 0.28; 95% CI odds = 0.09-0.89). CONCLUSIONS: The age-gender structure of the background population is not sufficient to explain the socio-demographic differences between migrant and British-born patients with SLP. Male patients may be more socially isolated.

Age of Onset↗

PubMed2005

Effects of social isolation stress on immune response and survival time of mouse with liver cancer.

AIM: To investigate the effects of isolation stress on mouse with liver cancer and possible associated mechanisms. METHODS: Transplantable murine hepatoma22 (H22) model was used to evaluate the effects of social isolation stress on murine liver cancer. Mice were immunized with sheep red blood cell (SRBC) and intraperitoneally inoculated with H22 cell, then divided into two groups, one reared individually as group (I) and the other reared in groups as group (G). Titer of antibody to SRBC and interleukin 2 (IL-2) in serum was monitored. The survival time of mouse with liver cancer was observed. RESULTS: The titer of antibody to SRBC in group (G) was 1:24.5 and that in group (I) was 1:11.2. There was a significant difference between these two groups (t = 2.60, P = 0.02). A significant difference in IL-2 concentration was observed between group (G) (39.6 ng/L) and group (I) (47.1 ng/L, t = 2.14, P = 0.046). The survival time in group (G) (16.5 d) was markedly longer than that in group (I) (13.2 d, t = 3.46, P = 0.002). CONCLUSION: Our study suggests that survival time of the mouse bearing H22 tumor is affected by the social isolation stress and the associated mechanism may be the immunological changes under the social isolation stress.

Animals↗

PubMed2004

Targeted mutation of CCK(2) receptor gene antagonises behavioural changes induced by social isolation in female, but not in male mice.

Neuropeptide cholecystokinin (CCK) regulates the adaptation of rodents in the novel environment. In the present study we analysed the behavioural changes induced by the individual housing in mice, lacking CCK(2) receptors. The wild-type (+/+) and homozygous (-/-) CCK(2) receptor deficient mice of both gender were used throughout the study. The weight gain during the 21-day isolation period and changes in the locomotor activity following the social separation were measured. The elevated plus-maze and resident/intruder tests were also performed to test alterations in the emotional behaviour. Social isolation induced locomotor hyperactivity, reduced weight gain and increased aggressiveness in the wild-type (+/+) and homozygous (-/-) male mice. In the wild-type (+/+) female mice the significant reduction of exploratory activity in the plus-maze was evident. By contrast, in female mice, lacking CCK(2) receptors, the exploration of the plus-maze was not significantly affected by the individual housing. This finding demonstrates that the social isolation does not cause anxiety-like state in the CCK(2) receptor deficient mice. Moreover, the targeted invalidation of CCK(2) receptors increased in male mice the affinity of dopamine D(2) receptors in the sub-cortical structures, whereas in female mice the increased affinity of 5-hydroxytryptamine(2) (5-HT(2)) receptors in the frontal cortex was established. The increased affinity of 5-HT(2) receptors is probably the compensatory change to the lack of CCK(2) receptors in female mice and probably reflects the reduced sensitivity of these animals to the anxiogenic manipulations. In conclusion, targeted mutation of CCK(2) receptors selectively antagonised the behavioural changes induced by the individual housing in females, but not in male mice.

Aggression↗

PubMed2001

Adaptation to social isolation. Acute and long-term stress responses of growing gilts with different coping characteristics.

The present experiment studied the acute and long-term stress responses of reactive and proactive prepubertal gilts to social isolation. Gilts with either reactive or proactive features were identified according to behavioral resistance in a backtest at a young age (2-4 days), respectively being low (LR) and high resistant (HR) in this test. At 7 weeks of age, 12 gilts of each type were socially isolated. Initially, isolation was stressful for both types of gilts, as shown by increased cortisol concentrations and decreased body temperatures. Moreover, both types reacted with increases in exploration and vocalizations. Stress responses to isolation, however, differed in magnitude and/or duration between LR and HR gilts, which was in line with expected reaction patterns on the basis of preferred ways of coping. The cortisol response to isolation was higher in LR gilts, and they generally showed more explorative behavior. HR gilts seemed to be more engaged in walking/running behavior in the first hour after isolation, they generally vocalized more and their noradrenaline excretion in urine was higher at 3 weeks after the start of isolation. Several responses to isolation in the longer term pointed to a prolonged higher general state of stress of HR gilts. Body temperature in HR gilts, for instance, did not recover during 3 weeks of isolation, but values returned to "normal" within 1 day in LR gilts. At 1 week of isolation, relatively high parasympathetic responsivity to novelty was observed in HR gilts, probably due to stress-related high sympathetic reactivity. A shift in percentages of leucocyte subsets, typically occurring under conditions of stress, only developed in HR gilts during isolation. Finally, gastric ulceration was found in one HR gilt, but did not occur in LR gilts. To conclude, LR and HR gilts differed in their strategies to adapt to social isolation, and especially for HR gilts, this procedure seemed to become a chronic stressor.

Acute Disease↗

PubMed2003

The social isolation of seafarers: causes, effects, and remedies.

The human element is increasingly acknowledged as an important factor contributing to accidents at sea. What is infrequently considered however, is the extent to which social isolation, and its effects on seafarers, contributes to both marine incidents and to the problems of seafarer retention currently experienced throughout the industry as a whole. This paper draws on the findings of several related studies undertaken at the Seafarers International Research Centre (1999-2002) along with a number of published studies on seafarer health. In doing so it considers both the causes and potential effects of social isolation on seafarers. These areas have not traditionally been subject to systematic scrutiny and analysis. As such they are substantially under-researched and are often under-emphasised by policy makers and practitioners in the maritime sector. Using participant observation and detailed qualitative studies the paper explores these issues in an effort to bring them on to the accident prevention agenda and to highlight the need for further detailed research in this area. In drawing to a conclusion the paper highlights a number of steps that could be taken by shipping companies to militate against social isolation and to encourage better mental health amongst modern day seafarers.

Humans↗

PubMed1995

Effects of prolonged social isolation on responses of neurons in the bed nucleus of the stria terminalis, preoptic area, and hypothalamic paraventricular nucleus to stimulation of the medial amygdala.

The studies presented demonstrate changes in hypothalamo-pituitary-adrenocortical secretion, and in electrical activity and synaptic responses of neurons in the bed nucleus of the stria terminalis, preoptic area, and hypothalamic paraventricular nucleus of rats exposed to early, long-term social isolation. Rats isolated from all social contact from an early preweaning time showed reduced basal plasma corticosterone concentrations, compared with littermate controls raised under social conditions. Isolated animals also exhibited a selective decrease in the spontaneous electrical activity of neurons within the hypothalamic paraventricular nucleus and lateral preoptic area, but not in adjacent structures. Moreover, isolation also altered the response of neurons in certain nuclei to electrical stimulation of the medial amygdala. Thus, a reduction in excitatory responses, and an increase in inhibition and nonresponsiveness, of preoptic area and paraventricular nucleus neurons was recorded, compared with control rats. Neurons in the bed nucleus of the stria terminalis were less affected, but showed an increase in the duration of excitatory responses following medial amygdala stimulation. These results, obtained from urethane-anesthetized rats, together with the reduced basal plasma corticosterone concentrations, suggest a reduction in limbic-hypothalamo-pituitary-adrenocortical (LHPA) activity following maternal deprivation and prolonged social isolation. This may result from altered limbic activity, specifically in the amygdala and its pathways to the paraventricular nucleus (PVN). Such alterations may include the stria terminalis, in so much as increased efficacy of inhibitory components and reduced efficacy of excitatory components was observed. The neural mechanisms underlying these alterations could involve an altered synaptology of the regions examined and/or a disruption of glucocorticoid feedback events.

Amygdala↗

PubMed2003

Brain-derived neurotrophic factor mRNA downregulation produced by social isolation is blocked by intrahippocampal interleukin-1 receptor antagonist.

Manipulations that increase the expression of the pro-inflammatory cytokine interleukin-1beta (IL-1beta) in the hippocampus (e.g. peripheral administration of lipopolysaccharide, i.c.v. glycoprotein 120, social isolation) as well as the intrahippocampal injection of IL-1beta following a learning experience, dramatically impair the memory of that experience if the formation of the memory requires the hippocampus. Here we employed social isolation to further study this phenomenon, as well as its relation to brain-derived neurotrophic factor (BDNF). BDNF was studied because of its well-documented role in the formation of hippocampally based memory. A 6 h period of social isolation immediately after contextual fear conditioning impaired memory for context fear measured 48 h later, and decreased BDNF mRNA in the dentate gyrus and the CA3 region of the hippocampus assessed immediately after the isolation. Moreover, an intrahippocampal injection of the IL-1 receptor antagonist prior to the isolation period prevented both the BDNF downregulation and the memory impairments produced by the isolation. These data suggest that hippocampal-dependent memory impairments induced by elevated levels of brain IL-1beta may occur via an IL-1beta-induced downregulation in hippocampal BDNF.

Animals↗

PubMed1976

Diazepam treatment of socially isolated monkeys.

Four rhesus monkeys were reared for the first eight months of life in total social isolation. One animal died during this period; the three remaining subjects were treated with diazepam in an isolation chamber, in their home cages, and in a playroom testing situation. Diazepam significantly decreased the self-disturbance behaviors of two subjects, and there was even the appearance of some social behaviors, although they were limited and not of the same quality as in nonisolated subjects. The authors discuss the implications of the data for understanding the significance of the social isolation syndrome in monkeys as a model for human psychoses.

Aggression↗

PubMed2006

Reducing social isolation in people with mental illness: the role of the psychiatrist.

OBJECTIVES: To determine the level of social isolation and the nature of close relationships among people with mental illness in contact with SANE Australia, and to assess the role of the psychiatrist in assisting in the reduction of social isolation. METHODS: A cross-sectional survey was conducted with 76 carers and 182 consumers via SANE Australia's helpline service, website or face-to-face during February and March 2005. RESULTS: Loneliness and social exclusion are major issues for Australians with mental illness who are in contact with SANE Australia. Almost three out of four respondents said that they, or the person they care for, experienced loneliness often, if not all the time. Consumers who attended psychosocial rehabilitation services regularly were more content with their close relationships than those who did not. Psychiatrists were identified as one of the preferred points of referral for psychosocial rehabilitation services. CONCLUSIONS: The separation between clinical treatment services and psychosocial rehabilitation programmes for people with mental illness has created a system that is fragmented and makes it easy for consumers to 'fall through the net'. For these reasons, there should be greater collaboration between psychosocial and clinical services. This will encourage psychiatrists to refer people to community programmes.

Adult↗

PubMed2005

Social isolation stress-induced aggression in mice: a model to study the pharmacology of neurosteroidogenesis.

Long-term social isolation of laboratory animals is a model to study the behavioral and neurochemical consequences of the absence of social interaction in rodents. Many of the symptoms induced by isolation resemble depression and anxiety disorder symptomatology. Our studies have revealed that male mice socially isolated for more than 4 weeks, exhibit increased aggressiveness, a reduced responsiveness to GABA(A) receptor acting drugs, and a downregulation of brain levels of 3alpha,5alpha-tetrahydroprogesterone (allopregnanolone: 3alpha,5alpha-THP), a neurosteroid endowed with potent positive allosteric modulatory activity of the action of GABA at various GABA(A) receptor subtypes. This downregulation of 3alpha,5alpha-THP appeared to be associated with the reduction of brain type I 5alpha-reductase mRNA and protein expression. Systemic administration of the selective serotonin reuptake inhibitor fluoxetine and its metabolite norfluoxetine normalized brain 3alpha,5alpha-THP content and reduced responsiveness to GABA(A) mimetic drugs in a stereospecific manner. These drugs in nanomolar doses also reduced social isolation-induced aggressiveness with the same stereospecificity as detected in their action on 3alpha,5alpha-THP brain content, while their ex vivo inhibition of serotonin reuptake occurred at high micromolar doses and lacked stereospecificity. From these results we infer that the brain 3alpha,5alpha-THP content physiologically upregulates GABA(A) receptor responsiveness to GABA and that social isolation induces a reduction of brain 3alpha,5alpha-THP content that is probably causally related to the onset of aggression.

Aggression↗

PubMed2004

Brain neurosteroids in gender-related aggression induced by social isolation.

Genetic, environmental, or hormonal factors and their interactions have been implicated in the expression of gender-related aggressive behavior in humans. Several independent lines of evidence support the role of hormonal and environmental factors in the aggressive behavior of experimental animals. Social isolation (SI) for 2-4 weeks in male but not in female mice results in the expression of aggression to a same-sex intruder. Long-term treatment (3 weeks) with anabolic steroids during SI in female mice induces aggressive behavior toward a male intruder of a severity similar to that observed in socially isolated (SI) male mice. The induced aggression in male and female mice is associated with a decrease of brain allopreg-nanolone (Allo). In SI male mice, aggression can be prevented by treatment with L-methionine (MET), which has also been shown to decrease reelin and GAD67 mRNA expression and maintain normal brain Allo content. The histone deacetylase inhibitor valproic acid can reverse this process, suggesting that histone tail acetylation may reverse the action of MET. We conclude that during social isolation, aggression can be controlled either by preventing Allo downregulation (e.g., by treatment with MET) or by direct administration of Allo or of agents (e.g., fluoxetine) that upregulate brain Allo content in SI mice.

Aggression↗

PubMed1996

Behavioral and pituitary adrenal-axis responses of dairy cows to social isolation and deprivation of lying down.

The behavior and plasma concentrations of ACTH and cortisol were studied in 30 Friesian cows kept in tie stalls and assigned to three treatments: control (C), deprivation of lying down from 0900 to 1600 and 2200 to 0500 (D), and social isolation (I). Behavior of the cows was observed before and after 4 and 8 wk of treatment. The D- and I-cows showed increased frequency of transitions between different behavioral activities (P < .05). In D- and I-cows the frequency of grooming (P < .01) and idling (P < .001), and the amount of leaning (P < .001) increased. In D-cows the frequency of eating was also increased. The behavior and cortisol response to two novel arena tests performed on two consecutive days after 22 d of treatment suggests that social isolation and deprivation of lying change cows' reactions to a novel environment. After 23 d of treatment, concentrations of ACTH and cortisol were measured during 7.5 h. On d 24, cortisol concentrations were determined at time -.5, 0, .5, 1, 2, 3, 4, and 5 h after i.v. administration of ACTH. Cortisol concentrations did not differ among treatment groups in the baseline series and after ACTH administration. In D-cows, ACTH concentration was increased in part of the baseline series (P < .05). The results suggest that the socially isolated cows were frustrated or tried to compensate for a lack of stimulation and that repeated deprivation of lying down is aversive to cows.

Adrenocorticotropic Hormone↗

PubMed2005

Social isolation stress impairs passive avoidance learning in senescence-accelerated mouse (SAM).

Despite cumulative evidence showing the detrimental effect of psychosocial stress on the learning/memory functions in dementia diseases, the precise neurobiological mechanisms behind such an effect remain unclear. Mice of the senescence-accelerated mice prone 10 (SAMP10) strain, a neurodegenerative dementia model, were chronically exposed to social isolation stress from the age of 5 weeks. At the age of 12 weeks, conditioning memory and spatial memory were evaluated by one-trial passive avoidance and Y-maze tests, respectively. Chronic social isolation stress significantly reduced conditioning memory but did not affect spatial memory. Although further behavioral tasks using an elevated plus maze and a pain threshold test exhibited stress-induced analgesia, an analysis of covariance excluded the possibility that such analgesia might contribute to the stress-induced impairment of conditioning memory. In addition, endocrinological and immunohistochemical analysis revealed that isolation stress elevated the serum corticosterone levels and inhibited the increase in c-Fos expression in the central amygdaloidal nucleus (CeA) that is required for conditioning memory during passive avoidance learning. In conclusion, chronic social isolation stress exacerbated conditioning memory in SAM mice, probably through a glucocorticoid-mediated decrease in neural activation in the CeA.

Aging↗

PubMedDate not supplied

The influence of social isolation on ethanol preference behavior and dopamine release in telencephalon slices in mice.

We examined the relation between the duration of social isolation and alterations in ethanol preference behavior and the dopamine release in telencephalon slices in mice. Ethanol preference developed only after an isolation period of 2 weeks and a further ethanol treatment of 2 weeks. It did not appear after an isolation period of 6 weeks, in mice without ethanol treatment, and in group-housed mice. The dopamine release was lowered in mice isolated for 2 weeks and is normalized in combination with ethanol treatment. The dopamine release inhibition evoked by social isolation of 2 weeks probably reflects a functional state with high sensitivity for induction of an ethanol preference behaviour.

Animals↗

PubMed2005

Species differences in anxiety-related responses in male prairie and meadow voles: the effects of social isolation.

Prairie (Microtus ochrogaster) and meadow voles (M. pennsylvanicus) are closely related species that differ in life strategy and social behaviors, and thus provide an excellent comparative model for the study of neuronal and hormonal mechanisms underlying behavior. In the present study using the elevated plus maze (EPM) test, we found that male prairie voles entered the open arms of the EPM more and remained there longer, and showed a higher level of overall locomotor activity than did male meadow voles. In addition, two weeks of social isolation induced an increase in open arm entries in prairie, but not meadow, voles. Prairie voles also had a higher level of circulating corticosterone compared to meadow voles, and the EPM test increased circulating corticosterone in prairie voles. Finally, social isolation coupled with the EPM test influenced Fos-immunoreactive expression in several brain areas, including the medial preoptic area, ventromedial hypothalamus, amygdala, and prefrontal cortex differently between the two species. Together, these data indicate a neural circuit involved in mediating anxiety-associated behavior in voles, and that the functioning of this circuit is influenced by social environment differently between social and non-social species.

Animals↗