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.     

Justifying a Curriculum and Justifying an Institution

ABSTRACT The recent revival of interest in theory leads the writers to examine a particular moment when a curriculum and the institution in which it occurred was explained and justified. Max Horkheimer's inaugural address to the Institute for Social Research in 1931 is summarised. The points made by the new Director of the Institute are examined in relation not only to his proposal for an inter-disciplinary curriculum, but also to the nature of the institution and to the general justification of higher education. The article concludes with a number of comments on the relevance of these proposals to some modern higher education issues.     

Barriers to Condom Use and Safer Sex Talk among College Dating Couples

Using an open-ended questionnaire response format, this study examined self-generated barriers to condom use and safer sex talk among 119 heterosexual college dating couples at the University of New Mexico (total N=238). Data were collected from both members of these dyads. Reasons for abstaining from intercourse were also elicited. Several general response categories emerged including no perceived risk; spontaneity; deliberate choice; negative attitudes; and a lack of perceived self-efficacy for enacting condom use and safer sex discussion. Explanations for abstinence included religious/moral prohibitions; lack of readiness for intercourse; and a fear of being emotionally hurt. Few differences emerged across gender, ethnicity (Caucasian vs Hispanic), and prior sexual experience (participant had intercourse prior to current relationship vs did not). Selected reasons for not using a condom and/or discussing safer sex (e.g. partner is monogamous) were cross-validated with the self-reported behavior of the respondent's dating partner. In general, participants reasons for perceived non-risk were not supported by their partner's reported behavior. Implications of these findings for sexual risk reduction programs include: establishing realistic goals for safer sex behavior and talk within committed relationships, acknowledging the impact of passion on safer sex, and addressing knowledge gaps in risk perception.