Hippocampal PKA/CREB pathway is involved in the improvement of memory induced by spermidine in rats

Spermidine (SPD) is an endogenous polyamine that modulates N-methyl-D-aspartate (NMDA) receptor function, and has been reported to facilitate memory formation. In the current study we determined whether or not the PKA/CREB signaling pathway is involved in SPD-induced facilitation of memory of inhibitory avoidance task in adult rats. The post-training administration of the cAMP-dependent protein kinase (PKA) inhibitor, N-[2-bromocinnamylamino)ethyl]-5-isoquinoline sulfonamide [H-89, 0.5 ρmol intrahippocampal (ih)] or the antagonist of the NMDA receptor polyamine-binding site (arcaine, 0.02 nmol ih) with SPD (0.2 nmol ih) prevented memory improvement induced by SPD. Intrahippocampal administration of SPD (0.2 nmol) facilitated PKA and cAMP response element-binding protein (CREB) phosphorylation in the hippocampus 180 min, but not 30 min, after administration, and increased translocation of the catalytic subunit of PKA into the nucleus. Arcaine (0.02 nmol) and H-89 (0.5 ρmol) prevented the stimulatory effect of SPD on PKA and CREB phosphorylation. These results suggest that memory enhancement induced by the ih administration of SPD involves the PKA/CREB pathways in rats.     

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org

Call for Papers

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org     

The Mediation Effect of Posttraumatic Stress Disorder Symptoms on the Relationship of Intimate Partner Violence and IFN-γ Levels

Background: Women who experience intimate partner violence (IPV) report greater stress and negative health consequences than nonabused women. Although an association between psychological stress and altered immune function has been shown, IPV studies have not investigated this relationship. Objective: This study explored the association of IPV with mental health symptoms and an immune marker to determine if posttraumatic stress disorder (PTSD) symptoms mediate the effect of IPV on pro-inflammatory (IFN-γ) cytokine levels. Methods: A cross-sectional, comparative design was used to compare 62 women with IPV and 39 nonabused women. Results: Mean IFN-γ values were higher in abused women and in women with current PTSD symptoms. There were no significant relationships with potential confounding variables that could provide an alternative explanation for the increase in production of proinflammatory cytokines. Conclusions: PTSD symptoms mediate the association between IPV and IFN-γ levels and may partially explain the association of mental health symptoms with physical health sequelae in IPV.     

Sexual risk as an outcome of social oppression: data from a probability sample of Latino gay men in three U.S. cities

Based on data from a probability sample of 912 Latino gay men in 3 U.S. cities, a multivariate model of sexual risk was tested, including experiences of homophobia, racism, and poverty as predictors. Participants reported multiple instances of verbal and physical abuse, rude mistreatment, and discrimination on account of their sexual orientation and their race or ethnicity. Many reported experiences of poverty, such as inability to pay for basic necessities of food or shelter. Men who reported more instances of social discrimination and financial hardship were more psychologically distressed and more likely to participate in "difficult" sexual situations, as predicted. Participation in difficult sexual situations mediates the effects of social oppression and psychological distress on sexual risk behavior.     

Methylphenidate Does Not Modify the Impact of Response Frequency or Stimulus Sequence on Performance and Event-Related Potentials of Children with Attention Deficit Hyperactivity Disorder

Twenty-six children with attention deficit/hyperactivity disorder (ADHD) participated in a double-blind trial consisting of 2 consecutive weeks each of placebo and methylphenidate (M = 26.92 mg/day = 0.78 mg/kg/day). As expected, stimulant therapy resulted in moderate weight loss, increased somatic complaints, and teacher and parent reports of reduced inattentiveness, aggression, and oppositionality. In both phases of the trial, patients were tested in a choice reaction time task assessing two aspects of the task that presumably affect response selection: response frequency (ratio of targets/nontargets = 25/75 vs. 50/50) and stimulus sequence (alternations vs. repetitions). Both manipulations yielded expected results on performance and event-related potentials (ERPs). Stimulant treatment increased accuracy and speed among younger children and curtailed variability of reaction time for the sample as a whole. However, methylphenidate did not affect ERPs. In combination, the results imply that the enhancement of performance by methylphenidate does not involve the demands of response selection examined in this study.     

Spontaneous object recognition in capuchin monkeys: assessing the effects of sex,familiarization phase and retention delay

Animal Cognition - The spontaneous object recognition (SOR) task is a versatile and widely used memory test that was only recently established in nonhuman primates (marmosets). Here, we extended...     

An extension of uncertainty management theory to the self: the relationship between justice, social comparison orientation, and antisocial work behaviors

A multisource field study of 103 employees and their supervisors tested an extension of uncertainty management theory (E. A. Lind & K. Van den Bos, 2002; K. Van den Bos & E. A. Lind, 2002). According to this theory, persons high in social comparison orientation (F. X. Gibbons & B. P. Buunk, 1999) experience chronic uncertainty about the self. It was hypothesized that this should strengthen the effects of interactional and procedural justice perceptions on antisocial work behaviors. As predicted, the negative relationship between employee perceptions of interactional justice and supervisory ratings of antisocial work behaviors was stronger for people who are high as compared with low in social comparison orientation. Results provide evidence for an extension of uncertainty management theory to the self-domain.     

Emotions,Public Opinion,and U.S. Presidential Approval Rates: A 5‐Year Analysis of Online Political Discussions

This article examines how emotional reactions to political events shape public opinion. We analyze political discussions in which people voluntarily engage online to approximate the public agenda: Online discussions offer a natural approach to the salience of political issues and the means to analyze emotional reactions as political events take place in real time. We measure shifts in emotions of the public over a period that includes 2 U.S. presidential elections, the 9/11 attacks, and the start of military action in Afghanistan and Iraq. Our findings show that emotional reactions to political events help explain approval rates for the same period, which casts novel light on the mechanisms that mediate the association between agenda setting and political evaluations.