Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

An information theory analysis of duration of lifeguards' scanning

Observers recorded the duration of scanning by six lifeguards in three indoor swimming pools. Duration of scanning was significantly predicted by the absolute numbers of child swimmers (< 17 years) in the pools and when numbers of child swimmers were represented in terms of bits of information. Duration of scanning increased as a linear function of both numbers of children and child bits of information. These results are interpreted in terms of the Hick-Hyman law of information theory. Lifeguards appear to simplify the task of information processing and decision-making by concentrating on children as a more at-risk group of swimmers. Duration of scanning was not significantly related to changes in number of adult swimmers.     

The Trouble with Harrison's 'The Trouble with Tarski'

In 'The Trouble with Tarski', The Philosophical Quarterly , 48 (1998), pp. 1–22, Jonathan Harrison attacks 'Tarski-style' truth theories for both formalized and natural languages, on the grounds that (1) truth cannot be a property of sentences; (2) if it could be, T-sentences would have to be necessary truths, which they are not; and (3) T-sentences are not necessarily true and can even can be false. I reply that (1) cannot be an objection to Tarskian truth theories, since these can be formulated in terms of whatever truth bearers might be. Thesis (2) is unjustified: Harrison's argument for it depends on an equivocation. Thesis (3) is false, since the right-hand side of a T-sentence is a meta-language translation of the object-language sentence described on the left-hand side, and this guarantees its truth.
email: boisvert@phil.ufl.edu     

Exploring unique roles for psychologists

Presents a comment on "Psychological Treatments" by D. H. Barlow. Barlow highlighted unique roles that psychologists can play in mental health service delivery by providing psychological treatments--treatments that psychologists would be uniquely qualified to design and deliver. In support of Barlow's position, the authors draw from their own clinical practice with special psychiatric populations, such as adults with severe and persistent mental illness and behaviorally disordered youths, to illustrate some potential unique roles for psychologists. The authors believe psychologists are uniquely trained to design such individualized functional behavioral analysis protocols because of their training in research design, behavior analysis, learning theory, and behavior change. Psychologists may also be uniquely qualified to design, implement, and evaluate many specialized therapy techniques, as Barlow has outlined and suggested.     

Validity of three measures of communication for predicting relationship adjustment and stability among a sample of young couples

The goal of this study was to examine whether data from 3 different measures of communication (i.e., self-report, quasi-observational, and observational) can predict relationship adjustment and stability 1 year later when used conjointly in a sample of 62 young couples. The 3 measures of communication were the Communication Skills Test--Revised (CST-R), the Communication Box (CB), and the Demand/Withdraw Pattern Questionnaire (DWPQ). Through hierarchical multiple regression analyses, results revealed that the CST-R and the DWPQ predict both genders' relationship adjustment 1 year later when used conjointly. Logistic regression analyses revealed that none of the measures of communication significantly predicted relationship stability. In conclusion, the combination of the CST-R and the DWPQ appears to be useful for longitudinally predicting relationship adjustment.     

The Effects of Stress and Social Support on Externalizing Behaviors Among Children in Military Families

Drawing on social support theory, this study examines the main and interactive effects of parental perceived stress and social support on externalizing behaviors in military youth. Findings reveal that not only do social support and stress affect the conduct of military children, but social support also moderately buffers the effects of parental stress. Given the increasing distance between military and American culture, more generally, this research is one opportunity to make sense of contradictory expectations about the well-being of military youth. In doing so, it provides implications for how a more supportive organization can benefit military families.     

The role of intergroup disgust in predicting negative outgroup evaluations

We introduce intergroup disgust as an individual difference and contextual manipulation. As an individual difference, intergroup disgust sensitivity (ITG-DS) represents affect-laden revulsion toward social outgroups, incorporating beliefs in stigma transfer and social superiority. Study 1 (5 samples, N = 708) validates the ITG-DS scale. Higher ITG-DS scorers demonstrated greater general disgust sensitivity, disease concerns, authoritarian/conservative ideologies, and negative affect. Greater ITG-DS correlated with stronger outgroup threat perceptions and discrimination, and uniquely predicted negative outgroup attitudes beyond well-established prejudice-predictors. Intergroup disgust was experimentally manipulated in Study 2, exposing participants (n = 164) to a travel blog concerning contact with a disgust-evoking (vs. neutral) outgroup. Manipulated disgust generated negative outgroup evaluations through greater threat and anxiety. This mediation effect was moderated: Those higher (vs. lower) in ITG-DS did not experience stronger disgust, threat, or anxiety reactions, but demonstrated stronger translation of aversive reactions (especially outgroup threat) into negative attitudes. Theory development and treatment implications are considered.     

Hypothalamo-Pituitary-Adrenocortical Regulation Following Lesions of the Central Nucleus of the Amygdala

Previous reports indicate that the central nucleus of the amygdala (CeA) stimulates adrenocorticotropin and corticosterone secretion, suggesting a role for this region in central hypothalamo-pituitary-adrenocortical (HPA) stress regulation. To evaluate this hypothesis, this study assessed the impact of CeA lesion on the response of hypophysiotrophic paraventricular nucleus (PVN) neurons to acute restraint and chronic unpredictable stress exposure. In contrast to previous reports, CeA lesions did not affect corticosterone or ACTH secretion induced by acute stress. Acute restraint increased PVN corticotropin releasing hormone (CRH) mRNA expression, increased the number of parvocellular PVN neurons expressing the co-secretagogue arginine vasopressin (AVP), and induced cFOS mRNA expression in the parvocellular PVN. However, there was no additional effect of CeA lesion on any measure of PVN activation. Chronic unpredictable stress exposure induced long-term activation of the HPA axis, noted by thymic involution, adrenal hypertrophy and increased PVN CRH mRNA expression. Stress-induced changes in thymus and adrenal weights were not affected by CeA lesion. Further, CeA lesion rats did not differ from controls in post-stress CRH mRNA expression. However, basal CRH mRNA expression was increased in the PVN of CeA rats, suggesting that the CeA plays a role in long-term inhibition of the PVN. The results of these studies are not consistent with the hypothesis that the CeA is necessary for stress-induced pituitary-adrenocortical activation. Rather, this region may play a stressor-specific modulatory role in regulation of HPA function.