Environmental enrichment results in cortical and subcortical changes in levels of synaptophysin and PSD-95 proteins

Experience-dependent plasticity is thought to involve selective change in pre-existing brain circuits, involving synaptic plasticity. One model for looking at experience-dependent plasticity is environmental enrichment (EE), where animals are exposed to a complex novel environment. Previous studies using electron microscopy showed that EE resulted in synaptic plasticity in the visual cortex and hippocampus. However, the areas in the brain that have been examined following EE have been limited. The present study quantified potential synaptic plasticity throughout the brains of C57BL/6 mice using an enzyme-linked immunosorbent assay (ELISA) for two synaptic proteins, synaptophysin and PSD-95. EE resulted in increased synaptophysin and PSD-95 levels through major brain regions, including anterior and posterior areas of the forebrain, hippocampus, thalamus, and hypothalamus. However, no changes in synaptophysin were detected in the cerebellum. These results demonstrate that EE results in an increase in levels of both pre- and post-synaptic proteins in multiple regions of the brain, and it is possible that such changes represent the underlying synaptic plasticity occurring in EE.     

Disturbances of consciousness in dementia with Lewy bodies associated with alteration in nicotinic receptor binding in the temporal cortex

Disturbances of consciousness, including fluctuations in attention and awareness, are a common and clinically important symptom in dementia with Lewy bodies (DLB). In the present study we investigate potential mechanisms of such disturbances of consciousness (DOC) in a clinicopathological study evaluating specific components of the cholinergic system. [3H]Epibatidine binding to the high-affinity nicotinic receptor in the temporal cortex (Brodmann's areas 20 and 36) differentiated DLB cases with and without DOC, being 62-66% higher in those with DOC (F=4.5,p=.025). The were no differences between DLB patients with or without DOC in 125I-labeled alpha-bungaratoxin binding to the low-affinity nicotinic receptor, [3H]pirenzepine binding to the muscarinic M1 receptor, or in choline acetyltransferase activity. These findings provide support for the hypothesis that cholinergic activity is an important neural correlate if consciousness and suggest a mechanism of DOC in DLB involving alterations in the nicotinic receptor, composed of predominantly alpha4 and beta2 subunits.     

Reinvigorating the Study of Careers

Before discussing how to innovate the study of career development using insights from life-span psychology and life course sociology, researchers might benefit from reconsidering whether they are studying careers or studying vocational behavior. While the word “career” seems ubiquitous in vocational psychology research, there are important differences between the study of vocational behavior, occupational roles, and career development. In this article, I urge researchers to (a) reconsider the meaning of career and research on career development, (b) adopt prospective, longitudinal research designs, and (c) concentrate first on processes of development and then on the content of careers. Considering these suggestions may ready vocational psychology for true innovations such as studying human development through work and relationships.     

Self-Presentation Concerns and Health Behaviors Among Cosmetic Surgery Patients

The present investigation examined the relationship between self-presentational motives and physical activity in a population of cosmetic surgery participants. Participants were 50 female and 5 male cosmetic surgery patients (CSPs; M age = 38.5 years) who completed a battery of self-report measures following either vein or acne treatment. Analyses revealed significant group differences on self-presentational concern and public self-consciousness between: (a) those who elected the treatment for appearance motives and those who elected treatment for health-based motives, and (b) the more frequent (3 or more times per week) and less frequent (2 or less times per week) exercisers. Greater self-presentational concerns and greater public self-consciousness were associated with having appearance-related motives for treatment and with being a less frequent exerciser.     

Rodney King and O. J. Revisited: The Impact of Race and Defendant Empathy Induction on Judicial Decisions

White university students participated in a study to investigate the impact of defendant race and empathetic induction on a subsequent juror decision-making task. Participants read a passage involving a Black or a White defendant in a criminal case. They were subsequently induced to feel no empathy, low empathy, or high empathy for the defendant. When compared to participants in the low- and control empathy conditions, those in the high-empathy condition reported greater target empathy, made attributions that were more situational, and assigned more lenient punishments. The results also indicate that group membership can moderate the impact of empathetic induction. When compared to the participants in the Black defendant condition, those in the White defendant condition reported greater target empathy, made attributions that were more situational, and assigned more lenient punishments. Implications for both empathy and judicial decision-making research are discussed.     

The Role of Prototypical Situations in the Perceptions of Prejudice of African Americans1

Inman and Baron (1996) found that African Americans and Whites possess prototypes for racist behavior that involve Whites oppressing African Americans. However, prototypical content may be more detailed and specific for African Americans because of differing cultural experiences. In the present experiment, undergraduates read stories about interpersonal encounters representing prototypical and nonprototypical situations. Actor race ambiguity was manipulated by the presence or absence of photographs. As expected, Whites tended to make equal ratings of prejudiced behavior for prototypical and nonprototypical situations. However, African Americans perceived more prejudice in prototypical vignettes than in nonprototypical vignettes. They also perceived stronger prejudicial displays and more dispositional motivation for targets in prototypical vignettes. The results suggest that African Americans have heightened sensitivity to prejudice in specific situations, a factor that may contribute to racial confrontations and misunderstandings.