Translocation and activation of Rac in the hippocampus during associative contextual fear learning

Small G proteins including Rac are mediators of changes in neuronal morphology associated with synaptic plasticity. Previous studies in our laboratory showed that Rac is highly expressed in the adult mouse hippocampus, a brain area that exhibits robust synaptic plasticity and is crucial for the acquisition of memories. In this study, we investigated whether Rac was involved in NMDA receptor-dependent associative fear learning in the area CA1 of adult mouse hippocampus. We found that Rac translocation and activation was increased in the hippocampus following associative fear conditioning in mice, and that these increases are blocked by intraperitoneal injection of the NMDA receptor channel blocker MK801 at the acquisition stage. Our data indicate that NMDA receptor-dependent associative fear learning alters Rac localization and function in the mouse hippocampus.     

Reinstatement of episodic-like memory in rats by neurokinin-1 receptor antagonism

We previously showed that a systemic administration of the selective non-peptide neurokinin-1-receptor (NK-1-R) antagonist SR140333 increases hippocampal acetylcholine levels and facilitates long term memory. In the present study, we investigated whether systemic SR140333 has beneficial effects on episodic-like memory for unique experiences. Rats received either no injection, a vehicle injection or SR140333 at doses of 1, 3 and 9 mg/kg (i.p.) prior to the acquisition of an object memory for what, where and when. In line with previous results, untreated rats showed episodic-like memory, while vehicle-injected rats were impaired. A low dose of 1mg/kg SR140333 reinstated episodic-like memory. This result might be related to the effects of SR140333 on hippocampal cholinergic transmission and/or on the stress-response elicited by the injection procedure. Higher doses of SR140333 (3 and 9 mg/kg) induced psychomotor effects, including stereotypic behaviors and arched posture. Since NK-1-R antagonists have anxiolytic and promestic properties and induce hippocampal acetylcholine release at lower doses, they might be effective in the alleviation of the cognitive deficits and increased anxiety seen in early stages of Alzheimer's disease.     

Behavioral Activation as an Early Intervention for Posttraumatic Stress Disorder and Depression Among Physically Injured Trauma Survivors

This paper describes an adaptation of behavioral activation (BA) for the early intervention of posttraumatic stress disorder (PTSD) and depression among physically injured survivors of traumatic injury, and presents pilot data on a small randomized effectiveness trial (N = 8). The application of BA to PTSD is based on the theory that increases in guided activity may break patterns of avoidance that can maintain PTSD. Compared to treatment as usual (TAU), those who received BA showed improvement in PTSD symptom severity from pre- to posttreatment, and there was a trend for the BA group to score better than the TAU group on physical functioning. Contrary to expectation, this brief adaptation did not have an impact on depression. Implications of these results for the effective early intervention after trauma are discussed.     

Prediction of longevity of volunteer service: a basic alternative proposal

A problem for many organizations is the low continuity of volunteers. Diverse theoretical models have been developed to explain sustained volunteerism, but most of these models have focused on the study of welfare volunteerism and not have verified whether their results could be generalized to other types of volunteerism. In this study, we propose a basic model to explain sustained volunteerism in any type of volunteerism. The aim of this study is to examine this basic model empirically in a sample of socio-assistential volunteers and in a sample of environmental volunteers. For this purpose, 290 volunteers completed a questionnaire and subsequently, two telephone follow-ups were carried out to determine whether the volunteers remained in the NGO one year later. The results show that the basic model offers an acceptable explanation of sustained volunteerism in the two types of volunteer samples studied, but it accounted for a low percentage of variance of the duration of service in both samples. Various relevant implications for the practical management of volunteerism in organizations are derived from theses findings.     

Presaccadic brain potentials in conditions of covert attention orienting

Twelve healthy subjects underwent investigation of averaged (electroencephalogram) EEG potentials during preparation for motor activity and in the latent period (LP) of visually evoked saccades by presentation of stimuli using Posner's (1980) design of "cost-benefit". It has been shown that covert spatial attention orientation leads to an increase in amplitude and decrease in latency of presaccadic initiation potential peaks within the saccadic latent period (LP) (P-100, N-50). Processes of covert orientation of attention during the interstimulus interval period of anticipation of the target stimulus correlate with the increase of slow negativity of fronto-parietal-temporal localization. Spatial-temporal changes of presaccadic potentials are evidence of the fact that orientation of attention during motor preparation and saccadic initiation is reflected in intensification of fronto-parietal networks of saccadic control and attention, activating the fronto-medio-thalamic and thalamo-parietal modulating systems.     

Visual attention as a predictor of on-road driving performance of older drivers

With increasing numbers of older drivers on Australian roads, it is important to determine the functional abilities most closely related to driving ability among older adults. To this end, 90 drivers aged from 60 to 91 completed a battery of psychological, visual, physical and cognitive tests, and a standardised on-road driving test. A computerised test of visual attention, devised specifically for the study, was the best predictor of on-road driving performance. Other abilities that made independent contributions to the prediction of driving performance were contrast sensitivity and visuospatial memory. These functional abilities provided a better prediction of driving performance than chronological age, reinforcing the argument that drivers should only have their driving tested when their functional abilities decline, rather than when they reach a particular age.     

The development of in-group favoritism: between social reality and group identity

This study examined how social reality restricts children's tendency for in-group favoritism in group evaluations. Children were faced with social reality considerations and with group identity concerns. Using short stories, in this experimental study, conducted among 3 age groups (6-, 8-, and 10-year-olds), the authors examined the trait attribution effects of reality constraints on eye-color differences and national group differences. The results show that the trait attributions of all age groups were restricted by the acceptance of socially defined reality. In addition, when the information about reality was not considered accurate, only the youngest children showed positive in-group favoritism. It is argued that these findings are useful in trying to reconcile some of the divergent and contrasting findings in the developmental literature on children's intergroup perceptions and evaluations.     

Take care! The evaluation of a team-based burnout intervention program for oncology care providers

In this quasi-experimental study among staff of 29 oncology wards, the authors evaluated the effects of a team-based burnout intervention program combining a staff support group with a participatory action research approach. Nine wards were randomly selected to participate in the program. Before the program started (Time 1), directly after the program ended (Time 2), and 6 months later (Time 3), study participants filled out a questionnaire on their work situation and well-being. Results of multilevel analyses showed that staff in the experimental wards experienced significantly less emotional exhaustion at both Time 2 and Time 3 and less depersonalization at Time 2, compared with the control wards. Moreover, changes in burnout levels were significantly related to changes in the perception of job characteristics over time.