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- All Subjects: Stress
- Creators: Department of Psychology
- Creators: Doane, Leah D
increases). At a different level of analysis, within-person increases in momentary stress level were significantly associated with increases in cortisol only for those with low trait levels of coping efficacy and engagement coping. On average, within-person increases in momentary NA were significantly associated with cortisol reactivity. Tests of moderation revealed this momentary association was only significant for those with low trait levels of support-seeking coping.
This hypothesis is supported by previous studies demonstrating that stress-induced elevation of glucocorticoids increases the transcription of C4. I propose that activated glucocorticoid receptors directly increase C4 protein expression as a transcription factor activator. Additionally, I propose that activated glucocorticoid receptors inhibit the expression of the transcription factor nuclear factor-light-chain-enhancer of activated B cells (NF-κB), thereby leading to decreased expression of the C4 inhibitor CUB and Sushi multiple domains 1 (CSMD1).
Glucocorticoid receptors and C4 are richly expressed in the hippocampus, a region critical in memory consolidation, spatial, and declarative memory. I propose that stress-induced upregulation of C4 activity in the hippocampus promotes excessive synaptic pruning, contributing to specific deficits and hippocampal shrinkage seen in schizophrenia. Stress exposure during fetal development and adolescence likely acts through the proposed mechanisms to increase hippocampal C4 activity and subsequent schizophrenia risk. These mechanisms may reveal novel interactions between environmental and genetic risk factors in the etiology of schizophrenia through complement activation.
Methods: 191 middle-aged adults from a community-based study on resilience were asked to complete 30 daily diaries assessing positive and negative affect. At least 6 months later, participants completed a phone interview that assessed distress (i.e., depressive and anxiety symptoms), well-being (i.e., WHO-5 well-being, vitality, social functioning), physical functioning, and perceived stress.
Results: A three-factor solution with latent factors representing overall, negative, and positive EC was identified. Overall EC significantly predicted enhanced physical functioning, but was not associated with distress or well-being. Contrary to study hypotheses, positive and negative EC were not associated with future distress, well-being, or physical functioning, though a trend toward improved physical functioning was noted for positive EC. In contrast, positive and negative ED were both associated with less distress, and better well-being and physical functioning. Overall ED was unexpectedly related to worse outcomes (i.e., more distress, less well-being, decreased physical functioning). Stress did not moderate the relationship between emotional complexity and the outcome variables.
Conclusions: Different indicators of EC represent distinct aspects of emotional experience. Partial support of the hypotheses found. Physical functioning was the only outcome influenced by EC. The inclusion of stress did not change the results. The discrepancy between the findings and those in the literature may be related to reliability of EC indicators and absence of contextual factors. Further exploration of ED revealed a potentially important construct of emotional experience that is deserving of further inquiry.
Exploration of a mouse model (C57BL/6J) capable of demonstrating behavioral changes after adolescent social isolation that are consistent with prior findings may prove beneficial in later research. This study examined 2 proposed long-term effects of isolated housing (one mouse/cage), when compared to group housing (two mice/cage) during adolescence. Mice were placed in their respective housing conditions after weaning (PND 21) and remained in those conditions until PND 60. The same cohorts were used in both phases of the experiment. Phase 1 sought to confirm previous findings that showed increases in ethanol intake after adolescent social isolation using a 2-bottle preference Drinking-in-the-Dark (DID) design over a 4-day period (PND 64-PND 67.). Phase 2 sought to elucidate the effects present after adolescent social isolation, as measured using response inhibition capabilities demonstrated during fixed-minimum interval (FMI) trials (PND 81-PND 111). Findings in phase 1 of the experiment were non-significant, save a strong tendency for female mice in both housing conditions to drink more as a proportion of their bodyweight (g/kg). However, a trend of lower bodyweight in single housed mice did exist, which does suggest that detrimental stress was applied via the used of adolescent isolation in that housing condition. Findings in phase 2 showed little effect of adolescent social isolation on mean inter-response time (IRT) at any criterion used (FMI-0, FMI-4, FMI-6). Evaluation of mean interquartile range (IQR) of IRTs showed a significantly greater amount of variation in IRT responses within single housed mice at the highest criterion (FMI-6), and a trend in the same direction when FMI-4 and FMI-6 were tested concurrently. Taken as a whole, the findings of this experiment suggest that the effect of adolescent social isolation on ethanol intake is far less robust than the effect of sex and may be difficult to replicate in a low-power study. Additionally, adolescent social isolation may interfere with the ability of mice to show consistent accuracy during FMI tasks or a delay in recognition of FMI criterion change.