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.     

Parent‐offspring conflict in Japan and parental influence across six cultures

Previous research has demonstrated that parents and children often have conflicting mate preferences. The present research was conducted among 443 Japanese university students. Using an existing scale designed to uncover parent‐offspring conflict over mate choice, the results revealed that children perceived having a potential partner with traits connoting poor genetic quality as being more unacceptable to themselves, and having a potential partner with traits connoting low parental investment and cooperation with the ingroup as being more unacceptable to their parent. A number of sex differences emerged. The highest potential for parent‐offspring conflict existed between female offspring and their father, and female offspring also rated traits connoting low social status as being more unacceptable to their parents, particularly to the father.     

Parents just don't understand: Parent-offspring conflict over mate choice

Previous research reveals that children and parents are not in complete agreement over which traits are most important for the mate of the child. Children tend to prefer traits that suggest genetic quality, whereas parents prefer characteristics that suggest high parental investment and cooperation with the ingroup. Using a sample of parents, mothers (n = 234) and fathers (n =240) the hypothesis was supported; parents perceived characteristics indicating a lack of genetic quality as being more unacceptable to the child, while characteristics indicating a lack of parental investment and cooperation with the ingroup were more unacceptable to themselves. Sex differences between mothers and fathers and sons and daughters were explored.     

2D:4D in men is related to aggressive dominance but not to sociable dominance

It has been shown that a smaller ratio between the length of the second and fourth digit (2D:4D) is an indicator of the exposure to prenatal testosterone (T). This study measured the 2D:4D of men and assessed dominance as a personality trait to investigate indirectly if the exposure to prenatal T is related to a dominant personality later in life. Results showed that men had a more aggressive dominant personality when having a more masculine (lower) 2D:4D, while there was no relationship between sociable dominance and 2D:4D. Findings from this study indicate that it is important to distinguish different forms of dominance since other studies failed to find relationships between dominance and 2D:4D.