Learning-induced arg 3.1/arc mRNA expression in the mouse brain

The effector immediate-early gene (IEG) arg 3.1, also called arc, encodes a protein interacting with the neuronal cytoskeleton. The selective localization of arg 3.1/arc mRNA in activated dendritic segments suggests that the arg 3.1/arc protein may be synthesized at activated post-synaptic sites and that arg 3.1/arc could participate in structural and functional modifications underlying cognitive processes like memory formation. To analyze whether learning itself is sufficient to trigger expression of arg 3.1/arc, we developed a one-trial learning paradigm in which mice learned to enter a dark compartment to escape from an aversively illuminated area. Arg 3.1/arc mRNA expression was analyzed by in situ hybridization in three groups of mice as follows: a control group with no access to the dark compartment, a learning group having access to the dark compartment for one trial, and a retrieval group having access to the dark compartment for two trials on consecutive days. All animals from the learning and retrieval groups escaped the illuminated area, and those tested 24 h later (retrieval group) showed a strongly reduced latency to enter the dark compartment, demonstrating the validity of our learning paradigm to induce long-term memory. Our results show that acquisition of a simple task results in a brain area-specific biphasic increase in arg 3.1/arc mRNA expression 15 min and 4.5 h post-training. This increase was detected specifically in the learning group but neither in the control nor in the retrieval groups. The pattern of arg 3.1/arc mRNA expression corresponds temporally to the two mRNA- and protein-synthesis-dependent periods of long-term memory formation. Our study provides the first unequivocal evidence that arg 3.1/arc expression is induced by a learning task and strongly suggests a role of arg 3.1/arc mRNA in the early and late cellular mechanisms underlying the stabilization of the memory trace.     

Diencephalic damage decreases hippocampal acetylcholine release during spontaneous alternation testing

A rodent model of diencephalic amnesia, pyrithiamine-induced thiamine deficiency (PTD), was used to investigate diencephalic-hippocampal interactions. Acetylcholine (ACh) release, a marker of memory-related activation, was measured in the hippocampus of PTD-treated and control rats prior to, during, and after spontaneous alternation test. During behavioral testing, all animals displayed increases in ACh release. However, both the percent increase of ACh release during spontaneous alternation testing and the alternation scores were higher in control rats relative to PTD-treated rats. Thus, when rats are tested on a task with demands dependent on the hippocampus, it appears that the hippocampus is not fully activated after diencephalic damage.     

Prevalence of Child and Adolescent Exposure to Community Violence

Emerging as one of the most significant health issues facing American youth today, child and adolescent exposure to community violence has generated much interest across multiple disciplines. Most research to date has focused on documenting the prevalence of community violence and the emotional and behavioral ramifications. This paper provides an overview of the current literature regarding prevalence of youth exposure to community violence, and identifies those areas where further research is warranted. In addition to examining overall rates of community violence exposure, this paper reviews the prevalence of different types of community violence, such as weapon use, physical aggression, and crime-related events. Predictors of community violence exposure, including gender, age, race, socioeconomic status, behavior patterns, and geography, are discussed.     

Making sense of self-conscious emotion: linking theory of mind and emotion in children with autism

Self-conscious emotions such as embarrassment and shame are associated with 2 aspects of theory of mind (ToM): (a) the ability to understand that behavior has social consequences in the eyes of others and (b) an understanding of social norms violations. The present study aimed to link ToM with the recognition of self-conscious emotion. Children with and without autism identified facial expressions conscious of self-conscious and non-self-conscious emotions from photographs. ToM was also measured. Children with autism performed more poorly than comparison children at identifying self-conscious emotions, though they did not differ in the recognition of non-self-conscious emotions. When ToM ability was statistically controlled, group differences in the recognition of self-conscious emotion disappeared. Discussion focused on the links between ToM and self-conscious emotion.     

Pathways of Economic Influence on Adolescent Adjustment

An important part of a science aimed at the prevention of human dysfunction involves the development of empirically based models that identify processes of risk for or protection from emotional distress or behavioral problems over time. The present study developed and evaluated such a model that proposed two pathways through which family economic pressure was expected to influence change in adolescent internalizing symptoms (depression and anxiety) during the period from the eighth to the tenth grades. A total of 377 rural families in a midwestern state provided data for the analyses. The results were generally consistent with the conceptual model in that family economic pressure increased adolescent perceptions of family economic hardship, which, in turn, reduced the adolescent's sense of control or mastery over time. Lowered mastery was associated with increases in emotional distress. Also consistent with the model, prior levels of mastery appeared to reduce the magnitude of economic stress experienced by the adolescent, whereas prior emotional distress intensified the economic stress process. Although gender differences were found in these processes, the overall pattern of results suggests that girls and boys are both at risk for internalizing problems when families experience economic pressure. Implicatios of the findings for the dvelopment of effective preventive interventions with financially stressed families in rural areas are discussed.     

Practical Memory Concerns of Older Adults

We examine practical memory concerns in a sample of community-dwelling older adults. Participants responded to open-ended questions that were designed to solicit information regarding memory self-efficacy, memory management, memory remediation, and fears about memory aging in adulthood. Results indicated that (a) important dates, such as birthdays and anniversaries, were easily remembered, but names were not; (b) external memory aids were used most frequently; (c) a desire to improve memory for names and certain types of verbal information was expressed; and (d) loss of independence emerged as a fear associated with memory aging. Implications of these findings for the design of strategies to improve everyday memory performance and clinical memory management in older adults are discussed.     

That’s the way the ball bounces: infants’ and adults’ perception of spatial and temporal contiguity in collisions involving bouncing balls

Three experiments investigated the perception of collisions involving bouncing balls by 7- and 10-month-old infants and adults. In previous research, 10-month-old infants perceived the causality of launching collisions (events in which one object moves along a smooth horizontal trajectory toward a second object, apparently launching it into motion) in relatively simple event contexts. In more complex event contexts, infants failed to discriminate among the events or respond to changes in individual features. Experiments 1 and 2 of the present investigation revealed that 7- and 10-month-old infants attended to spatial and temporal contiguity, but not causality, in collisions involving the movement of bouncing balls. In Experiment 3, both spatiotemporal contiguity and general knowledge about movement trajectories influenced adults’ judgments of causality for these collisions. The present results add to a growing understanding of infants’ event perception as constructive and a function, in part, of the complexity of the event context.     

Mother Knows Best? Mother and Child Report of Behavioral Difficulties of Children of HIV-Infected Mothers

Children of HIV-infected mothers have more psychosocial adjustment difficulties than do those of noninfected mothers. In this study, child psychosocial adjustment in children of HIV-infected women is examined across the three stages of HIV-infected: asymptomatic, symptomatic and AIDS. Participants were 99 HIV-infected women and 148 noninfected women. Children were not identified as being HIV infected. Mother and child reports of behavioral difficulties are compared, and competing hypotheses about mother report of child behavior difficulties are tested. Results indicate an ascending linear trend for child report of internalizing and externalizing difficulties from the noninfected stage through increasingly severe stages of HIV-infection. According to mother report, child externalizing and internalizing difficulties are nonlinear, as mothers report an increase through the infected symptomatic stage, then a decrease in the AIDS stage. Implications for assessment, prevention and intervention in families with maternal HIV infection are discussed.