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.     

The general psychophysical differential equation: A comparison of three specifications

The general psychophysical differential equation, dy/dx = W₂(y)/W₁(x), with the solution y = f(x), where x and y are subjective variables and W₁ and W₂ their subjective Weber functions, is (a) compared with a corresponding functional equation, and (b) studied from a stochastic point of view by error calculus, Methods for evaluating and handling divergences are proposed and illustrated for a number of combinations of Weber functions. It is shown that either the differential: and the functional equations have the same solution or the difference between the solutions is negligible compared to empirical scatter. The error calculus gives the same result: either no error at all or a negligible one.     

Experiences of longing in Norwegian and Swedish 4- and 5-year-old children

Longing can be defined as a blend of the primary emotions of happiness and sadness. These primary emotions are experienced very early by children, and the meanings of the words happiness and sadness are also known by children early in their verbal development. To find out at what age children are able to understand and use the more developed concept of longing, the authors interviewed 74 preschoolers (4- and 5-year-olds) in Norway and Sweden about their experiences of longing. Chi-square analyses showed age and sex differences in knowledge of the concept, and some differences between categories of longing were also significant. Results showed that young children's ability to understand and use the concept of longing appears to be limited and that girls seem to mature earlier in this respect than boys do.     

Place learning in scopolamine-treated rats: the roles of distal cues and catecholaminergic mediation

Experiments 1 and 2 tested the hypothesis that cholinergic receptor antagonists impair place learning in a water maze by interfering with the processing of distal, visual cues. Extramaze cues were offered to rats in the form of geometrical patterns arranged on the inner circumference of a curtain surrounding the water maze. In Experiment 1 the animals were offered both the distal cues and proximal cues in the form of pingpong balls in fixed positions on the surface of the water while only distal cues were present in Experiment 2. Animals were injected with either scopolamine (0.5 mg/kg body wt) or saline 20 min prior to the daily place learning sessions. Upon reaching criterion level performance the animals were tested on "rotation" sessions on which the distal cues were displaced. The outcome of such "rotations" demonstrated that-regardless of the presence or absence of proximal cues-scopolamine-treated rats relied at least as much as normal animals on the distal cues. The acquisition phase of both Experiments 1 and 2 demonstrated an almost complete lack of scopolamine-associated impairment in acquisition and performance of the place learning task. In Experiment 3 (when scopolamine was no longer administered) the subjects of Experiment 2 were exposed to a series of pharmacological "challenges" of their place learning performance and eventually to surgical ablation of the anteromedial prefrontal cortex. The outcome of the pharmacological challenges and the postoperative test of task performance demonstrated that the place learning performance of animals which had acquired the task under scopolamine was mediated by a neural substrate dissimilar to the substrate of task performance in normal animals. Rats acquiring the task while deprived of the cholinergic system demonstrated above-normal contributions to task mediation from catecholaminergic-probably dopaminergic-mechanisms and tentative results pointed to a "shift" toward prefrontal task mediation.     

Validation of a single-item measure of usual physical activity

The purpose of this study was to assess the reliability and validity of a single-item measure of Usual Physical Activity and to assess its usefulness as a physical activity tool for perimenopausal women. 188 perimenopausal women participated (age: M = 47 yr., SD = 3; range = 40-55). Data were collected using the Women's Health Assessment Scale, the Physical Activity Questionnaire, the Perimenopause-related Quality of Life Scale, a health history and demographic questionnaire, and the rater. Scores were stable over a 2-wk. interval. Convergent validity was supported by a correlation of .66 between ratings on Usual Physical Activity and the Physical Activity Questionnaire. Concurrent validity was supported by the association of the rating of Usual Physical Activity with three parameters of Body Mass Index, psychosomatic symptoms, and perimenopause related quality of life, known to be associated with physical activity. Highly active women had a lower Body Mass Index than less active and inactive women. Active women tended to report fewer and less distressing psychosomatic symptoms and better quality of life. These findings support the use of rating of Usual Physical Activity to classify perimenopausal women into categories of physical activity.     

Different sources of loneliness are associated with different forms of psychopathology in adolescence

The present study investigated associations between loneliness in different social relationships and indicators of psychopathology in adolescence. A nationally representative sample of 1009 high school students completed measures of three types of loneliness and six indicators of psychopathology. Results indicated that peer-related and family-related loneliness were associated with depression, anxiety, and suicide ideation, whereas peer-related and romantic loneliness were associated with social phobia. In contrast, only family-related loneliness was associated with deliberate self-harm and eating disorders. It is important, therefore, to distinguish between experiences of loneliness in different social relationships, in particular the peer versus the family setting, when investigating loneliness and psychopathology in adolescence.