Metaplastic effect of apamin on LTP and paired-pulse facilitation

In area CA1 of hippocampal slices, a single 1-sec train of 100-Hz stimulation generally triggers a short-lasting long-term potentiation (S-LTP) of 1–2 h. Here, we found that when such a train was applied 45 min after application of the small conductance Ca²⁺-activated K⁺ (SK) channel blocker apamin, it induced a long-lasting LTP (L-LTP) of several hours, instead of an S-LTP. Apamin-induced SK channel blockage is known to resist washing. Nevertheless, the aforementioned effect is not a mere delayed effect; it is metaplastic. Indeed, when a single train was delivered to the Schaffer’s collaterals during apamin application, it induced an S-LTP, like in the control situation. At the moment of this LTP induction (15th min of apamin application), the SK channel blockage was nevertheless complete. Indeed, at that time, under the influence of apamin, the amplitude of the series of field excitatory postsynaptic potentials (fEPSPs) triggered by a stimulation train was increased. We found that the metaplastic effect of apamin on LTP was crucially dependent on the NO-synthase pathway, whereas the efficacy of the NMDA receptors was not modified at the time of its occurrence. We also found that apamin produced an increase in paired-pulse facilitation not during, but after, the application of the drug. Finally, we found that the induction of each of these two metaplastic phenomena was mediated by NMDA receptors. A speculative unitary hypothesis to explain these phenomena is proposed.     

Developmental changes in gender composition of friendship networks in adolescent girls and boys

This article describes both normative changes and individual differences in the gender composition of girls' and boys' friendship networks across adolescence and predicts variations in these changes. It also examines changes in the characteristics (context, age difference, closeness, and support) of same- and other-sex friendships in the network. Girls and boys (N=390) were interviewed annually from Grades 6 to 10 (76% retention). Growth in the proportion of other-sex friends was significantly more pronounced for girls and was related to different predictors for girls and boys. Moreover, over time, girls had other-sex friends that were increasingly older than themselves, and most of these friendships took place outside of the school, which was not the case for boys. Growth in the proportion of other-sex friends was more pronounced for secondary than for best friends. Finally, both girls and boys reported receiving higher levels of help from girls than from boys. These findings suggest that other-sex friendships might place some of the girls on a problematic developmental trajectory.     

An examination of the role of perceived support and employee commitment in employee-customer encounters

The authors examined the relationships between perceived organizational support, organizational commitment, commitment to customers, and service quality in a fast-food firm. The research design matched customer responses with individual employees' attitudes, making this study a true test of the service provider-customer encounter. On the basis of a sample of matched employee-customer data (N = 133), hierarchical linear modeling analyses revealed that perceived organizational support had both a unit-level and an employee-level effect on 1 dimension of service quality: helping behavior. Contrary to affective organizational commitment, affective commitment to customers enhanced service quality. The 2 sub-dimensions of continuance commitment to the organization--perceived high sacrifice and perceived lack of alternatives--exerted effects opposite in sign: The former fostered service quality, whereas the latter reduced it. The implications of these findings are discussed within the context of research on employee-customer encounters.     

Different action patterns for cooperative and competitive behaviour

The aim of the present study is to elucidate the influence of context on the kinematics of the reach-to-grasp movement. In particular, we consider two basic modes of social cognition, namely cooperation and competition. In two experiments kinematics of the very same action - reaching-to-grasp a wooden block - were analyzed in two different contexts provided by a cooperative task and competitive task. For the 'cooperation' tasks two participants were required to reach and grasp their respective objects and to cooperate to join the two objects in specific configurations in the middle of the working surface. For the 'competition' tasks, the two participants had to compete to place their own object first in the middle of the working surface. Results revealed specific kinematic patterns for cooperation and competition which were distinct from similar actions performed by each participant in isolation. Further, during the cooperation tasks, a high level of correlation between key kinematical parameters of the two participants was found. In accordance with evidence from neuroimaging, developmental and social psychology our results suggest the existence of motor patterns which reflect the intention to act in a social context.     

Control-group study of an intervention training program for youth suicide prevention

Few studies have examined whether training can improve competency in intervening with suicidal youths. In this study we attempted to verify the effectiveness of such a training program on helper competency. Forty-three helpers who received the training were compared with 28 helpers who did not. Participants who received the training improved in knowledge, attitudes, and intervention skills following the training, compared with the control group across measures. Their gains were maintained at 6-month follow-up. In this sample, implementation of a one-time training program improved helpers' competencies in youth suicide intervention.     

Which Helper Behaviors and Intervention Styles are Related to Better Short‐Term Outcomes in Telephone Crisis Intervention? Results from a Silent Monitoring Study of Calls to the U.S. 1–800‐SUICIDE Network

A total of 2,611 calls to 14 helplines were monitored to observe helper behaviors and caller characteristics and changes during the calls. The relationship between intervention characteristics and call outcomes are reported for 1,431 crisis calls. Empathy and respect, as well as factor-analytically derived scales of supportive approach and good contact and collaborative problem solving were significantly related to positive outcomes, but not active listening. We recommend recruitment of helpers with these characteristics, development of standardized training in those methods that are empirically shown to be effective, and the need for research relating short-term outcomes to long-term effects.     

Immigrant children's peer acceptance and victimization in kindergarten: The role of local language competence

The study investigates peer acceptance and victimization of immigrant and Swiss children in kindergarten classes. Our first aim is to compare peer acceptance and victimization of Swiss and immigrant children. Secondly, we explore the role of their local language competences (LLCs). The sample was drawn from kindergartens in communities in the German‐speaking part of Switzerland. A representative sample of 568 boys and 522 girls (mean age 5.8 years) took part in the research. Teachers completed questionnaires on children's victimization, bullying, and LLC. The nationality background of parents was indicated by teachers and parents. To assess peer acceptance, a peer nomination method was used. Immigrant children showed less acceptance by peers and were more often victimized than their Swiss peers. There was a significant interaction effect for LLC and national background of mothers, showing that LLC was positively associated with peer acceptance for children of an immigrant background but not for Swiss children. Furthermore, peer acceptance mediated the effect of national background of mothers on victimization. Results are discussed in terms of the need to improve immigrant children's LLC.     

The personal myth: A re‐evaluation

This paper presents a re‐evaluation of Kris's personal myth. The notion has been used rather sparingly despite the Delphi Symposium in 1984 on the question of its clinical usefulness. After framing the notion of myth, some difficulties related to the question are identified. A clinical vignette exemplifies some of the ambiguities in its definition but stresses its clinical relevance. A discussion expands on these situations so as to propose three various aspects of personal myths to account for the two variants identified by Kris. The actualization of the underlying fantasy in the character organization is a third form and the technical aspect associated with it is reviewed from a new perspective. The family romance is revisited to reassess its role as the basis of the personal myth in the face of studies favouring an earlier development of the myth.