Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

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.     

Is Low Anxiety Part of the Psychopathy Construct?

Low anxiety has traditionally been considered a feature of psychopathy, but there has been mixed research support for this conceptualization. We investigated the PPI-R-SF Stress Immunity subscale (a measure of low anxiety) in relation to 2 widely used self-report psychopathy scales in a sample of 346 undergraduate students. Results indicated that PPI-R-SF Stress Immunity was nearly unrelated to other indicators of psychopathy, showing a near-zero loading on the common psychopathy factor defined jointly by the scales of the PPI-R-SF and SRP-III. Stress Immunity also showed a pattern of personality and temperament correlates much different from those of other psychopathy subscales. Finally, Stress Immunity had a slight negative correlation with self-reports of diverse antisocial acts. These results suggest that despite its historical importance in the conceptualization of psychopathy, low anxiety is likely not a core feature of psychopathy.     

大学二年级学生人际宽恕与报复心理及其与抑郁的关系研究

采用沉思量表、报复动机量表、宽恕倾向量表、宽恕态度量表和流调中心用抑郁量表对236名大二学生进行问卷调查,综合探讨大学生人际宽恕和报复心理及其与抑郁的关系。研究发现:(1)男大学生的报复倾向显著高于女大学生。(2)宽恕倾向与报复倾向及对侵犯的沉思程度显著负相关。沉思程度和抑郁显著正相关。(3)沉思程度和宽恕倾向对抑郁分别具有显著的正向和负向的预测作用。(4)大学生的宽恕倾向和宽恕态度的相互作用以及宽恕倾向和报复倾向之间的交互作用对抑郁均没有显著预测作用。     

Do You Think You're Sexy,Tall, and Thin? The Prediction of Self‐Rated Attractiveness,Height, and Weight

Research suggests that self‐reports of personal attributes, including physical characteristics, are often distorted. The present study examined discrepancies between self‐ and observer or actual reports of attractiveness, height, and weight, and investigated the role of esteem and gender role scales in the prediction of such discrepancies. Results indicated that attractiveness discrepancies were predicted by high esteem and traditional gender roles, height discrepancies were predicted by agency, and weight discrepancies were predicted by personal efficacy. Results also indicated that esteem and gender role characteristics are important in the perception of self‐relevant information.     

Information processing bias against emotional facial expressions in social anxiety

The present study examined whether information processing bias against emotional facial expressions is present among individuals with social anxiety. College students with high (high social anxiety group; n  = 26) and low social anxiety (low social anxiety group; n  = 26) performed three different types of working memory tasks: (a) ordering positive and negative facial expressions according to the intensity of emotion; (b) ordering pictures of faces according to age; and (c) ordering geometric shapes according to size. The high social anxiety group performed significantly more poorly than the low social anxiety group on the facial expression task, but not on the other two tasks with the nonemotional stimuli. These results suggest that high social anxiety interferes with processing of emotionally charged facial expressions.     

Psychopathic Sexuality: The Thin Line Between Fantasy and Reality

In two studies, we explored the relations between psychopathic traits and sexual fantasy content. In Study 1, we rated content themes in the fantasy narratives of 195 men and women recruited at a Canadian university. In Study 2, we administered a sexual fantasy questionnaire to a sample of 355 Canadian undergraduate students. In Study 1, we found that psychopathic traits predicted themes of anonymous, uncommitted, and nonromantic sexual activity after controlling for participant sex. In Study 2, we found that psychopathy added to the prediction of self‐reported engagement in unrestricted, dominant, submissive, deviant, and adventurous sexual activity, even after controlling for participant sex and level of fantasizing about that activity. Furthermore, an interaction between psychopathy and level of fantasizing was observed for unrestricted and deviant sexual behavior, such that participants who reported high levels of fantasizing about these sexual themes were more likely to engage in that behavior if they also reported high levels of psychopathic traits. These findings suggest that psychopathy is related not only to interest in particular sexual behaviors, but also to whether individuals will translate these fantasized behaviors into reality.     

Phobic tendency within the Five-Factor and HEXACO models of personality structure

Recent research has indicated that the various specific phobias are only modestly correlated with the personality dimensions of the Big Five or Five-Factor Model (B5/FFM). We tested the hypothesis that the specific phobias would be more strongly associated with the dimensions of an alternative framework, the HEXACO model of personality structure. Self-reports on the Phobic Stimuli Response Scales (PSRS) were obtained along with self- and peer reports on measures of the B5/FFM and HEXACO dimensions from a sample of 248 non-clinical participants. The PSRS variables assessing specific phobias showed stronger correlations with the HEXACO Emotionality factor than with any B5/FFM dimension, and a stronger multiple correlation with the HEXACO factors than with the B5/FFM dimensions. Findings were similar across self- and peer reports of the personality variables. The results suggest that phobic tendency can be understood in terms of normal personality variation as conceptualized in the HEXACO framework.