Developmental Origins of Stress and Psychiatric Disorders

Psychophysiological responses to psychological stress exposure and neural correlates in adults with mental disorders: a scoping review

Introduction

The dysregulation of psychophysiological responses to mental stressors is a common issue addressed in individuals with psychiatric conditions, while brain circuit abnormalities are often associated with psychiatric conditions and their manifestations. However, to our knowledge, there is no systematic overview that would comprehensively synthesize the literature on psychophysiological responses during laboratory-induced psychosocial stressor and neural correlates in people with mental disorders. Thus, we aimed to systematically review the existing research on psychophysiological response during laboratory-induced stress and its relationship with neural correlates as measured by magnetic resonance imaging techniques in mental disorders.

Methods

The systematic search was performed on PubMed/Medline, EBSCOhost/PsycArticles, Web of Science, and The Cochrane Library databases during November 2021 following the PRISMA guidelines. Risk of bias was evaluated by employing the checklists for cross-sectional and case-control studies from Joanna Briggs Institute (JBI) Reviewers Manual.

Results

Out of 353 de-duplicated publications identified, six studies were included in this review. These studies were identified as representing two research themes: (1) brain anatomy and psychophysiological response to mental stress in individuals with mental disorders, and (2) brain activity and psychophysiological response to mental stress in individuals with mental disorders.

Conclusions

Overall, the evidence from studies exploring the interplay between stress psychophysiology and neural correlates in mental disorders is limited and heterogeneous. Further studies are warranted to better understand the mechanisms of how psychophysiological stress markers interplay with neural correlates in manifestation and progression of psychiatric illnesses.

Construction and Analysis of Human Diseases and Metabolites Network

The relationship between aberrant metabolism and the initiation and progression of diseases has gained considerable attention in recent years. To gain insights into the global relationship between diseases and metabolites, here we constructed a human diseases-metabolites network (HDMN). Through analyses based on network biology, the metabolites associated with the same disorder tend to participate in the same metabolic pathway or cascade. In addition, the shortest distance between disease-related metabolites was shorter than that of all metabolites in the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic network. Both disease and metabolite nodes in the HDMN displayed slight clustering phenomenon, resulting in functional modules. Furthermore, a significant positive correlation was observed between the degree of metabolites and the proportion of disease-related metabolites in the KEGG metabolic network. We also found that the average degree of disease metabolites is larger than that of all metabolites. Depicting a comprehensive characteristic of HDMN could provide great insights into understanding the global relationship between disease and metabolites.

Neuropeptides and oligopeptidases in schizophrenia

Schizophrenia (SCZ) is a complex psychiatric disorder with severe impact on patient's livelihood. In the last years, the importance of neuropeptides in SCZ and other CNS disorders has been recognized, mainly due to their ability to modulate the signaling of classical monoaminergic neurotransmitters as dopamine. In addition, a class of enzymes coined as oligopeptidases are able to cleave several of these neuropeptides, and their potential implication in SCZ was also demonstrated. Interestingly, these enzymes are able to play roles as modulators of neuropeptidergic systems, and they were also implicated in neurogenesis, neurite outgrowth, neuron migration, and therefore, in neurodevelopment and brain formation. Altered activity of oligopeptidases in SCZ was described only more recently, suggesting their possible utility as biomarkers for mental disorders diagnosis or treatment response. We provide here an updated and comprehensive review on neuropeptides and oligopeptidases involved in mental disorders, aiming to attract the attention of physicians to the potential of targeting this system for improving the therapy and for understanding the neurobiology underlying mental disorders as SCZ.

Metabolomics Analyses of 14 Classical Neurotransmitters by GC-TOF with LC-MS Illustrates Secretion of 9 Cell-Cell Signaling Molecules from Sympathoadrenal Chromaffin Cells in the Presence of Lithium

The classical small molecule neurotransmitters are essential for cell-cell signaling in the nervous system for regulation of behaviors and physiological functions. Metabolomics approaches are ideal for quantitative analyses of neurotransmitter profiles but have not yet been achieved for the repertoire of 14 classical neurotransmitters. Therefore, this study developed targeted metabolomics analyses by full scan gas chromatography/time-of-flight mass spectrometry (GC-TOF) and hydrophilic interaction chromatography-QTRAP mass spectrometry (HILIC-MS/MS) operated in positive ionization mode for identification and quantitation of 14 neurotransmitters consisting of acetylcholine, adenosine, anandamide, aspartate, dopamine, epinephrine, GABA, glutamate, glycine, histamine, melatonin, norepinephrine, serine, and serotonin. GC-TOF represents a new metabolomics method for neurotransmitter analyses. Sensitive measurements of 11 neurotransmitters were achieved by GC-TOF, and three neurotransmitters were analyzed by LC-MS/MS (acetylcholine, anandamide, and melatonin). The limits of detection (LOD) and limits of quantitation (LOQ) were assessed for linearity for GC-TOF and LC-MS/MS protocols. In neurotransmitter-containing dense core secretory vesicles of adrenal medulla, known as chromaffin granules (CG), metabolomics measured the concentrations of 9 neurotransmitters consisting of the catecholamines dopamine, norepinephrine, and epinephrine, combined with glutamate, serotonin, adenosine, aspartate, glycine, and serine. The CG neurotransmitters were constitutively secreted from sympathoadrenal chromaffin cells in culture. Nicotine- and KCl-stimulated release of the catecholamines and adenosine. Lithium, a drug used for the treatment of bipolar disorder, decreased the constitutive secretion of dopamine and norepinephrine and decreased nicotine-stimulated secretion of epinephrine. Lithium had no effect on other secreted neurotransmitters. Overall, the newly developed GC-TOF with LC-MS/MS metabolomics methods for analyses of 14 neurotransmitters will benefit investigations of neurotransmitter regulation in biological systems and in human disease conditions related to drug treatments.

Menstrual cycle irregularity and menopause status influence cognition in women with schizophrenia

Cognitive impairments are a core feature of schizophrenia and contribute significantly to functional complications. Current pharmacological treatments do not ameliorate cognitive dysfunction and the aetiology of cognitive impairments are poorly understood. Hormones of the hypothalamic-pituitary-gonadal (HPG) axis that regulate reproductive function have multiple effects on the development, maintenance and function of the brain and have been suggested to also influence cognition. The aim of the current study was to investigate how HPG axis hormones effect cognition, specifically exploring the influence of menopause status and menstrual cycle irregularity on cognitive performance in women with schizophrenia. The data for the present study represents pooled baseline data from three clinical trials. Two hundred and forty female participants with a diagnosis of schizophrenia or schizoaffective disorder were included in the analysis. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status. Hormone assays for serum sex steroids and pituitary hormones (including estradiol, progesterone, luteinising hormone and follicle-stimulating hormone) were conducted and women were classified as postmenopausal; perimenopausal; premenopausal/reproductive, further classified into regular and irregular menstrual cycles. To model a comparison of cognitive performance for i) perimenopausal; ii) post-menopausal women and iii) reproductive aged women with irregular cycles to reproductive aged women with regular cycles a semiparametric regression model (generalised additive mode) was fitted. The results revealed that in females with schizophrenia, menstrual cycle irregularity predicted significantly poorer cognitive performance in the areas of psychomotor speed, verbal fluency and verbal memory. Perimenopause was not associated with cognitive changes and the post-menopausal period was associated with poorer visuospatial performance. This study provides evidence to associate reproductive hormones with cognitive dysfunction in schizophrenia.