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.     

Psychosocial mediators of a theory-based resistance training maintenance intervention for prediabetic adults

Objective: Examine psychosocial mediators of the effects of high vs. low-dose resistance training (RT) maintenance interventions among older (ages 50–69), overweight and pre-diabetic adults.

Design: Participants (N = 123) completed a three-month supervised RT initiation phase and were subsequently randomised (time 1) to high or low-dose six-month unsupervised RT maintenance interventions (time 2), followed by a six-month no-contact phase (time 3).

Main Outcome Measures: Online measures of putative mediators and RT behaviour.

Results: RT intervention condition (high vs. low dose) had significant effects on change from time 1 to time 2 in behavioural expectation, self-regulation and perceived satisfaction (f² = .04–.08), but not outcome expectancies, RT strategies or behavioural intentions (f² ≤ .02). Change in each of the putative mediators, except for outcome expectancies (f² ≤ .02), had significant effects on RT behaviour at times 2 (f² = .12–.27) and 3 (f² = .23–.40). In a multiple mediation model, behavioural expectation (f² = .11) and self-regulation (f² = .06) mediated the effects of RT intervention condition on time 2 RT behaviour, whereas perceived satisfaction did not (f² = .01). Self-regulation was a significant mediator of intervention effects on time 3 RT behaviour (f² = .11), but behavioural expectation and perceived satisfaction were not (f² = .04).

Conclusions: Findings suggest that behavioural expectation and self-regulation are appropriate targets for RT maintenance interventions among at-risk older adults.     

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。     

Knowledge activation after information encoding: Implications of trait priming on person judgment

It is widely assumed that traits primed after the encoding of person information do not lead to assimilation effects on the judgment of that person. The authors challenge this view by providing evidence that post-encoding trait primes can result in assimilative person judgments under certain conditions. In Experiments 1 and 2, we identify the conditions under which these assimilation effects occur. Experiment 1 shows the importance of participants’ goals during person information encoding: assimilation is observed when person information is encoded as part of a memorization goal (as opposed to an impression formation goal). The findings of Experiment 2 further reveal that the encoded person information should imply trait concepts rather than being merely vague with respect to the primed trait category. Finally, the results of Experiment 3 suggest that the obtained assimilation effect is driven by differential accessibility for prime-congruent person information.     

Layoffs,self-esteem,and survivor guilt: Motivational,affective, and attitudinal consequences

The present study explored the effect of layoffs on the subsequent productivity of “survivors”. All participants performed a proofreading task either after witnessing the dismissal of a co-worker (Layoff condition) or not (No-Layoff condition). Consistent with equity theory, the quantity of workers' performance was greater in the Layoff than in the No-Layoff condition. A Worker Self-Esteem × Layoff interaction effect revealed that the Layoff effect was entirely attributable to the low, rather than the medium or high, self-esteem participants. Additional analyses revealed that the layoff caused participants to (1) experience increased feelings of remorse and (2) develop more negative attitudes toward their co-worker, both of which are also consistent with equity theory. Practical and theoretical implications are discussed.     

Équivalence échelle composite – échelle globale dans la mesure de la satisfaction au travail

We measured work satisfaction within the same sample (n=12) using two different methods : the one-item-scale global measure and the facet-scales composite measure. Results showed that the global scale is not equivalent to summated facet scales. This results can be explained by the fact that composite measures don’t take into account the proper weight of each facet in the computation of general work satisfaction. Considering limits presented by mixed measures in order to show up this weights, we advocate the development of a work satisfaction composite measure that integrates the measure of the importance allocated to each facet of work in the computation of general work satisfaction.     

Amplitude modulation of sexy phrases is salient for song attractiveness in female canaries (Serinus canaria)

Song discrimination and recognition in songbird species have usually been studied by measuring responses to song playbacks. In female canaries, Serinus canaria, copulation solicitation displays (CSDs) are used as an index of female preferences, which are related to song recognition. Despite the fact that many studies underline the role of song syntax in this species, we observed that short segments of songs (a few seconds long) are enough for females to discriminate between conspecific and heterospecific songs, whereas such a short duration is not sufficient to identify the syntax rules. This suggests that other cues are salient for song recognition. In this experiment, we investigated the influence of amplitude modulation (AM) on the responses (CSDs) of female canaries to song playbacks. We used two groups of females: (1) raised in acoustic isolation and (2) raised in normal conditions. When adult, we tested their preferences for sexy phrases with different AMs. We broadcast three types of stimuli: (1) songs with natural canary AM, (2) songs with AM removed, or (3) song with wren Troglodytes troglodytes AM. Results indicate that female canaries prefer and have predispositions for a song type with the natural canary AM. Thus, this acoustic parameter is a salient cue for song attractiveness.     

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.