Attenuation of Hippocampal 11beta-Hydroxysteroid Dehydrogenase Type 1 by Chronic Psychosocial Stress in the Tree Shrew

11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1) catalyses the interconversion of active cortisol and corticosterone with inert cortisone and 11-dehydrocorticosterone, thus regulating glucocorticoid access to intracellular receptors. In rats, chronic glucocorticoid excess or stress increases 11beta-HSD-1 in the hippocampus, producing suggestions that it may attenuate the deleterious effects of chronic glucocorticoid excess. However, 11beta-HSD-1 predominantly catalyses 11beta-reduction in the intact liver and hippocampal cells, thus regenerating active glucocorticoids from inert substrate. We studied 11beta-HSD activity in the tissues of male tree shrews following 28 days of sustained psychosocial stress or exogenous administration of cortisol. In the hippocampus, chronic psychosocial stress attenuated 11-HSD-1 activity (69 +/- 9% of control), whereas cortisol alone had no effect. In the liver, both chronic stress and cortisol administration decreased 11beta-HSD-1 activity (47 +/- 11% and 49 +/- 4% fall, resp.). Attenuation of 11beta-HSD-1 within tissues may reflect a homeostatic mechanism designed to minimise the adverse effects of prolonged stress and/or glucocorticoid excess.     

Mood-congruent biases in facial emotion perception and their gender dependence

Due to mood-congruency effects, we expect the emotion perceived on a face to be biased towards one's own mood. But the findings in the scant literature on such mood effects in normal healthy populations have not consistently and adequately supported this expectation. Employing effective mood manipulation techniques that ensured that the intended mood was sustained throughout the perception task, we explored mood-congruent intensity and recognition accuracy biases in emotion perception. Using realistic face stimuli with expressive cues of happiness and sadness, we demonstrated that happy, neutral and ambiguous expressions were perceived more positively in the positive than in the negative mood. The mood-congruency effect decreased with the degree of perceived negativity in the expression. Also, males were more affected by the mood-congruency effect in intensity perception than females. We suggest that the greater salience and better processing of negative stimuli and the superior cognitive ability of females in emotion perception are responsible for these observations. We found no evidence for mood-congruency effect in the recognition accuracy of emotions and suggest with supporting evidence that past reports of this effect may be attributed to response bias driven by mood.     

Regulation of glutamate synapses by nicotinic acetylcholine receptors in auditory cortex

Acetylcholine plays an important role in regulating the processing of sensory stimuli, and understanding its specific cellular actions is critical to understanding how sensory cortex develops and functions in different behavioral states. Here we review recent work on the cellular effects of nicotinic receptor activation in auditory cortex and describe how these actions could affect systems-level auditory function. In particular, we describe a novel function of nicotinic acetylcholine receptors to regulate glutamate synapses containing N-methyl-D-aspartate receptors during early postnatal development. The transient regulation of developing glutamate synapses also defines a window of vulnerability during which exposure to exogenous nicotine disrupts synapse development. Thus, it appears that nicotinic regulation of glutamate synapses is a critical feature of auditory cortex development.     

Chunking During Learning of Visuomotor Sequences with Spatial and Arbitrary Rules: Preliminary Findings

Visuomotor sequence learning requires participants to learn a two-fold process of learning the correct visuomotor transformation (spatial or arbitrary rules) and learning the correct order of performing the sequence. A motor sequence is performed with a specific timing pattern by grouping a number of elementary movements into chunks. The present research extends previous findings examining whether chunking phenomenon is observable for visuo-motor sequences with arbitrary transformations in addition to spatially defined targets. This research tests for dominant chunking patterns and individual variability.     

When Good Consumers Turn Bad: Psychological Contract Breach in Committed Brand Relationships

To better understand the conditions under which committed consumers continue to support their preferred brand after a transgression versus turn against the brand and the underlying theoretical process, we study the interplay between brand commitment and specific types of transgressions. Across three scenario‐based and field studies, we show that consumers have psychological contracts with brands, which dictate the terms of the relationship, and for committed consumers, violations of any aspect in (out of) the contract results in a negative (indifferent) response. Furthermore, we demonstrate that consumer trust is the underlying mechanism: committed consumers exhibit more negative responses to in‐contract transgressions as a result of their lower trust in the brand.     

Attitude towards euthanasia in relation to death anxiety among a sample of 343 nurses in India

Scores on Attitude towards Euthanasia were correlated with scores on Death Anxiety among 343 female nurses in India using Templer's Death Anxiety Scale and the authors' 24-item attitude scale. No significant correlation was found between the two sets of scores (r = -.09) or a nonlinear score on relation. Age of nurses was not significantly related to Attitude towards Euthanasia (r = .07) or Death Anxiety (r = .11). As measured, death anxiety has no bearing on attitude about euthanasia.     

Nicotinic acetylcholine receptors in sensory cortex

Acetylcholine release in sensory neocortex contributes to higher-order sensory function, in part by activating nicotinic acetylcholine receptors (nAChRs). Molecular studies have revealed a bewildering array of nAChR subtypes and cellular actions; however, there is some consensus emerging about the major nAChR subtypes and their functions in sensory cortex. This review first describes the systems-level effects of activating nAChRs in visual, somatosensory, and auditory cortex, and then describes, as far as possible, the underlying cellular and synaptic mechanisms. A related goal is to examine if sensory cortex can be considered a model system for cortex in general, because the use of sensory stimuli to activate neural circuits physiologically is helpful for understanding mechanisms of systems-level function and plasticity. A final goal is to highlight the emerging role of nAChRs in developing sensory cortex, and the adverse impact of early nicotine exposure on subsequent sensory-cognitive function.     

Test Anxiety Scale: reliability among Ethiopian students

Sarason's Test Anxiety Scale, translated into an Ethiopian language, was administered to 391 students in Grade 8 and to 422 students in preparatory school (Grades 11 and 12). In the first sample, 32 items loaded above the 0.3 criterion of acceptable item-remainder correlations and Cronbach alpha of .84. In the second sample, Cronbach alpha was .84 for the 34 items, but only 19 items had acceptable item-remainder correlations. The internal consistency reliabilities were comparable with those reported in the literature. However, the results of confirmatory factor analyses with extraction of four factors did not confirm the item loadings on factors as reported in the literature. Younger students (Grade 8) were found to have higher mean Test Anxiety than Grades 11 and 12 students. The Amharik version of the Test Anxiety Scale as a whole could be considered reliable and useful for Ethiopian students.