Neuroepigenetics of Prenatal Psychological Stress

Chronic Ultrasound Prenatal Stress Altered the Brain's Neurochemical Systems in Newborn Rats

Prenatal stress (PS) affects the development and functioning of the central nervous system, but the exact mechanisms underpinning this effect have not been pinpointed yet. A promising model of PS is one based on chronic exposure of pregnant rodents to variable-frequency ultrasound (US PS), as it mimics the PS with a psychic nature that most adequately captures the human stressors in modern society. The aim of this study was to investigate the effects of US PS on the brain neurotransmitter, neuropeptide, and neurotrophic systems of newborn Wistar rats. We determined the concentration of neurotransmitters and their metabolites (serotonin, HIAA, dopamine, DOPAC, and norepinephrine), neuropeptides (α-MSH, β-endorphin, neurotensin, oxytocin, and substance P), and the neurotrophin brain-derived neurotrophic factor (BDNF) in rat brain tissues by HPLC-ED, ELISA, and multiplex ELISA. Correlation analysis and principal component analysis (PCA) were used to get a sense of the relationship between the biochemical parameters of the brain. The results demonstrated that US PS increases the concentration of serotonin (p=0.004) and DOPAC (p=0.04) in the hippocampus has no effect on the neurotransmitter systems of the frontal cortex, reduces the concentration of BDNF in the entirety of the brain of males (p=0.008), and increases the neuropeptides α-MSH (p=0.02), β-endorphin (p=0.01), oxytocin (p=0.008), and substance P (p < 0.001) in the entire brain. A degree of complexity in the neurotransmitter system network in the frontal cortex and network change in the hippocampus after exposure to US PS have been observed. PCA revealed a similar pattern of neurotransmitter system interactions in the frontal cortex and hippocampus in males and females after exposure to US PS. We suggest that US PS can alter neurodevelopment, which is mediated by changes in the studied neurochemical systems that thus affect the behavioral phenotype in animals.

Exploring links between Chinese military recruits' psychological stress and coping style from the person-environment fit perspective: The chain mediating effect of self-efficacy and social support

The choice of coping style of recruits under psychological stress in the process of military task execution has been an important topic in the promotion of military operations and cohesion of military forces. Taking a positive coping style under psychological stress can help recruits overcome the negative effects of stress and improve military morale and group combat effectiveness. Although soldiers' psychological stress in the process of military mission execution having an impact on coping style has been studied by a large body of literature, very little literature has focused on the mechanism of self-efficacy and social support between recruits' psychological stress and coping style from the person-environment fit perspective. Therefore, this study was conducted to analyze the impact of recruits' psychological stress on coping style through a chain mediation model and to discuss the role of self-efficacy and social support in this relationship. Two waves of survey data were utilized to test the research hypotheses on a sample of 1028 Chinese recruits performing military tasks. The results indicated that recruits' psychological stress negatively impacted positive coping styles and positively correlated with negative ones. In addition, self-efficacy and social support mediated the relationship between psychological stress and positive coping style, and self-efficacy mediated the relationship between psychological stress and negative coping style. More importantly, self-efficacy and social support play the chain mediating effect between psychological stress and positive coping style.

Neuroepigenetics of Mental Illness: The Inside Outs of the Outside Within

Epigenetics refers to environmentally sensitive modifications to DNA and chromatin that regulate gene transcription without altering the genetic sequence itself. Because of the brain's central role in a person's adaptation to dynamic changes in the environment, the field of epigenetic research is particularly pertinent for the neurosciences and mental health and illness. "Neuroepigenetics" refers to the field of epigenetics, as applied to research of the nervous system and related functional abilities. The onset and course of mental disorders revolve around person-environment interactions, i.e., the interplay between environmental factors with people (and their brain) throughout life and on the background of an individual's inherited genomic make-up. With respect to the nervous system and its functional abilities, neuroepigenetic research aims to turn the inside outs by explicating the epigenetic profiles that regulate gene expression within cells while epigenetic profiles themselves may reflect the imprints of external factors (the outside of the organism). Neuroepigenetic research is of prime importance for elucidating the molecular underpinnings of gene-environment interplay in relation to functional abilities of the brain and mental health throughout life, and thus for identifying the mechanisms underlying onset and course of mental disorders. However, neuroepigenetic research is still in its infancy and many conceptual and methodological challenges are apparent. In addition, there are considerable complexities and major challenges in conceptualizing the nature and diagnosis of mental disorders, and these need to be taken into account in studying neuroepigenetics of mental disorders. The current manuscript provides an overview and conceptual framework for neuroepigenetic research in mental disorders.