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.     

Don't leave me: the effect of dependency and emotions in relationship conflict

Two studies examined how the effect of dependency and emotions on the dynamics of relationship conflict differs between men and women. In Study 1, 96 women and 67 men were presented with conflict situations that might occur in their relationship; the probability of aggression, anger, and dependency was measured. Results showed that anger mediated the relationship between dependency and the intention to use aggression, in men, but not in women. In Study 2, 95 women and 65 men wrote about a conflict situation that they had experienced with their partner; loyalty, guilt, and dependency were measured. Results showed that dependency predicted loyalty among women, and that this effect was mediated by guilt.     

The relationship between self-reported oral symptoms and life-events

Abstract

This paper investigates whether eight specific life-events were related to self-reported chronic (persistent trouble over the last 12 months) and acute (trouble in the last 14 days) oral symptoms in a sample of 3861 civil servants aged 35-44 years. The results of a logistic regression analysis taking age, social class and gender into account showed that a range of life-events—marital or family problems other than divorce, death of a relative, personal serious illness, serious illness of a close relative, major financial difficulty and mugging and robbery—were significantly associated with either acute or chronic oral symptoms. Further analysis showed that marital or family problems other than divorce was found to be the most important life event studied. The results support the argument that marital dissatisfaction leads to poorer physical and psychological health.     

On the learnability of frequent and infrequent word orders: An artificial language learning study

Most languages have a basic or "canonical" word order, which determines the relative positions of the subject (S), the verb (V), and the object (O) in a typical declarative sentence. The frequency of occurrence of the six possible word orders among world languages is not distributed uniformly. While SVO and SOV represent around 85% of world languages, orders like VSO (9%) or OSV (0.5%) are much less frequent or extremely rare. One possible explanation for this asymmetry is that biological and cognitive constraints for structured sequence processing make some word orders easier to be processed than others. Therefore, the high frequency of these word orders would be related to their higher learnability. The aim of the present study was to compare the learnability of different word orders between groups of adult subjects. Four artificial languages with different word orders were trained: two frequent (SVO, SOV) and two infrequent (VSO, OSV). In a test stage, subjects were asked to discriminate between new correct sentences and syntax or semantic violations. Higher performance rates and faster responses were observed for more frequent word orders. The results support the hypothesis that more frequent word orders are more easily learned.     

How do respondents construe ambiguous response formats of affect items?

Ambiguous response formats predict correlations from -.467 to -1 between opposite items, depending on whether the respondent's interpretation of the format is unipolar or bipolar. The authors present a procedure to investigate the proper interpretation in each case. It consists of applying nonparametric and parametric item response theory models (the Mokken and the graded response models) to pairs of opposite items in order to find the locations of the response options along the latent scale and, therefore, identify the response format construction. The authors tested this procedure on 4 samples (Ns=142-1,150) and 2 item pairs ("relaxed"-"tense" and "optimistic"-"pessimistic"). The results revealed that respondents constructed the formats as bipolar and supported the bipolarity of the item pairs.     

Effect of schedule and magnitude of reinforcement on instrumental learning in the toad, Bufo arenarum

Extinction after training with continuous (CR) or 50% partial (PR) reinforcement, and with different magnitudes of reward, was studied in the amphibian Bufo arenarum, in a runway situation. In Experiment 1, a group of toads received massed-trial, CR training with access to water as the reward. Performance improved during acquisition, including an improvement on the first trial of each session. Extinction was rapid and there was evidence for spontaneous recovery of the running response. In Experiment 2, groups of toads received PR or CR training at a rate of one trial per day. PR impaired acquisition and resulted in poor responding during extinction, compared to CR. Experiment 3 factorially studied the effects of schedule (PR vs CR) and distribution of practice (15 s vs 300 s intertrial interval). Acquisition was impaired by PR training but had little effect on extinction performance. Different magnitudes of water reinforcement were used in Experiment 4 in a one-trial-per-day situation. Terminal acquisition performance was a monotonic function of reward magnitude, but there were no differences in extinction performance across groups. The results are discussed in relation to comparative and developmental data on the paradoxical effects of reward.