A person-centered approach to the assessment of early life stress: Associations with the volume of stress-sensitive brain regions in early adolescence

AbstractResearchers are becoming increasingly interested in linking specific forms of early life stress (ELS) to specific neurobiological markers, including alterations in the morphology of stress-sensitive brain regions. We used a person-centered, multi-informant approach to investigate the associations of specific constellations of ELS with hippocampal and amygdala volume in a community sample of 211 9- to 13-year-old early adolescents. Further, we compared this approach to a cumulative risk model of ELS, in which ELS was quantified by the total number of stressors reported. Using latent class analysis, we identified three classes of ELS (labeled typical/low, family instability, and direct victimization) that were distinguished by experiences of family instability and victimization. Adolescents in the direct victimization class had significantly smaller hippocampal volume than did adolescents in the typical/low class; ELS classes were not significantly associated with amygdala volume. The cumulative risk model of ELS had a poorer fit than did the person-centered model; moreover, cumulative ELS was not significantly associated with hippocampal or amygdala volume. Our results underscore the utility of taking a person-centered approach to identify alterations in stress-sensitive brain regions based on constellations of ELS, and suggest victimization is specifically associated with hippocampal hypotrophy observed in early adolescence.

Download Full-text

The Effects of Early Life Stress on the Brain and Behaviour: Insights From Zebrafish Models

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.657591 ◽

2021 ◽

Vol 9 ◽

Author(s):

Helen Eachus ◽

Min-Kyeung Choi ◽

Soojin Ryu

Keyword(s):

Life Stress ◽

Early Life ◽

Early Life Stress ◽

Brain Regions ◽

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Current Status ◽

Comprehensive Overview ◽

Behavioural Changes ◽

The Brain

The early life period represents a window of increased vulnerability to stress, during which exposure can lead to long-lasting effects on brain structure and function. This stress-induced developmental programming may contribute to the behavioural changes observed in mental illness. In recent decades, rodent studies have significantly advanced our understanding of how early life stress (ELS) affects brain development and behaviour. These studies reveal that ELS has long-term consequences on the brain such as impairment of adult hippocampal neurogenesis, altering learning and memory. Despite such advances, several key questions remain inadequately answered, including a comprehensive overview of brain regions and molecular pathways that are altered by ELS and how ELS-induced molecular changes ultimately lead to behavioural changes in adulthood. The zebrafish represents a novel ELS model, with the potential to contribute to answering some of these questions. The zebrafish offers some important advantages such as the ability to non-invasively modulate stress hormone levels in a whole animal and to visualise whole brain activity in freely behaving animals. This review discusses the current status of the zebrafish ELS field and its potential as a new ELS model.

Download Full-text

Long-Term Decreases in the Expression of Calcineurin and GABAA Receptors Induced by Early Maternal Separation Are Associated with Increased Anxiety-Like Behavior in Adult Male Rats

Developmental Neuroscience ◽

10.1159/000512221 ◽

2020 ◽

pp. 1-10

Author(s):

Maryam Mahmoodkhani ◽

Maedeh Ghasemi ◽

Leila Derafshpour ◽

Mohammad Amini ◽

Nasrin Mehranfard

Keyword(s):

Anxiety Disorders ◽

Glutamate Receptors ◽

Life Stress ◽

Early Life ◽

Maternal Separation ◽

Central Area ◽

Early Life Stress ◽

Brain Regions ◽

Male Rats ◽

Lower Percentage

Introduction: Early life stress is a well-described risk factor of anxiety disorders in adulthood. Dysfunction in GABA/glutamate receptors and their functional regulator, calcineurin, is linked to anxiety disorders. Here, we investigated the effect of early life stress, such as repeated maternal separation (MS; 3 h per day from postnatal day [P] 2 to 11), on changes in the expression of calcineurin as well as the ionotropic glutamatergic and GABAergic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA) and GABAA receptors in the hippocampus and prefrontal cortex (PFC) of adolescent (P35) and adult (P62) male Wistar rats and their correlations with anxiety-like behavior in adulthood. Methods: The protein levels were assessed by Western blot analysis. Anxiety-like behavior was measured in the elevated plus maze (EPM) and open field (OF) tests. Results: MS induced a regional transient decrease of glutamate receptors expression at P35, with decreased NMDA and AMPA receptor levels, respectively, in the hippocampus and PFC, suggesting a possible decrease in excitatory synaptic strength. In contrast to glutamate receptors, MS had long-lasting influence on GABAA receptor and calcineurin levels, with reduced expression of GABAA receptor and calcineurin in both brain regions at P35 that continued into adulthood. These results were accompanied by increased anxiety behavior in adulthood, shown by lower percentage of number of total entries and time spent in the open arms of the EPM, and by lower time spent and number of entries in the OF central area. Conclusions: Together, our study suggests that GABAA receptors via calcineurin-dependent signaling pathways may play an important role in the expression of stress-induced anxiety-like behavior.

Download Full-text

Early-life stress and inflammation: A systematic review of a key experimental approach in rodents

Brain and Neuroscience Advances ◽

10.1177/2398212820978049 ◽

2020 ◽

Vol 4 ◽

pp. 239821282097804

Author(s):

Ethan G. Dutcher ◽

E.A. Claudia Pama ◽

Mary-Ellen Lynall ◽

Shahid Khan ◽

Menna R. Clatworthy ◽

...

Keyword(s):

Systematic Review ◽

Life Stress ◽

Early Life ◽

Maternal Separation ◽

Early Life Stress ◽

Later Life ◽

Interleukin 10 ◽

Brain Regions ◽

Clinical Approach ◽

Necrosis Factor Alpha

Repeated maternal separation is the most widely used pre-clinical approach to investigate the relationship between early-life chronic stress and its neuropsychiatric and physical consequences. In this systematic review, we identified 46 studies that conducted repeated maternal separation or single-episode maternal separation and reported measurements of interleukin-1b, interleukin-6, interleukin-10, tumour necrosis factor-alpha, or microglia activation and density. We report that in the short-term and in the context of later-life stress, repeated maternal separation has pro-inflammatory immune consequences in diverse tissues. Repeated maternal separation animals exhibit greater microglial activation and elevated pro-inflammatory cytokine signalling in key brain regions implicated in human psychiatric disorders. Notably, repeated maternal separation generally has no long-term effect on cytokine expression in any tissue in the absence of later-life stress. These observations suggest that the elevated inflammatory signalling that has been reported in humans with a history of early-life stress may be the joint consequence of ongoing stressor exposure together with potentiated neural and/or immune responsiveness to stressors. Finally, our findings provide detailed guidance for future studies interrogating the causal roles of early-life stress and inflammation in disorders such as major depression.

Download Full-text