Prenatal stress and brain development

Prenatal stress impacts foetal neurodevelopment: Temporal windows of gestational vulnerability

Prenatal maternal stressors ranging in severity from everyday occurrences/hassles to the experience of traumatic events negatively impact neurodevelopment, increasing the risk for the onset of psychopathology in the offspring. Notably, the timing of prenatal stress exposure plays a critical role in determining the nature and severity of subsequent neurodevelopmental outcomes. In this review, we evaluate the empirical evidence regarding temporal windows of heightened vulnerability to prenatal stress with respect to motor, cognitive, language, and behavioural development in both human and animal studies. We also explore potential temporal windows whereby several mechanisms may mediate prenatal stress-induced neurodevelopmental effects, namely, excessive hypothalamic-pituitary-adrenal axis activity, altered serotonin signalling and sympathetic-adrenal-medullary system, changes in placental function, immune system dysregulation, and alterations of the gut microbiota. While broadly defined developmental windows are apparent for specific psychopathological outcomes, inconsistencies arise when more complex cognitive and behavioural outcomes are considered. Novel approaches to track molecular markers reflective of the underlying aetiologies throughout gestation to identify tractable biomolecular signatures corresponding to critical vulnerability periods are urgently required.

Prenatal stress alters transcription of NMDA-type glutamate receptors in the hippocampus

Prenatal stress increases the risk of neurodevelopmental disorders. NMDA-type glutamate receptor (NMDAR) activity plays an important pathophysiological role in the cortico-hippocampal circuit in these disorders. We tested the hypothesis that transcription of NMDAR subunits is modified in the frontal cortex (FCx) and hippocampus after exposure to prenatal restraint stress (PRS) in mice. At 10 weeks of age, male PRS offspring (n = 20) and non-stressed controls (NS, n = 20) were treated with haloperidol (1 mg/kg), clozapine (5 mg/kg) or saline twice daily for 5 days, before measuring social approach (SOC). Saline-treated and haloperidol-treated PRS mice had reduced SOC relative to NS (P < 0.01), but clozapine-treated PRS mice had similar SOC to NS mice. These effects of PRS were associated with increased transcription of NMDAR subunits encoded by GRIN2A and GRIN2B genes in the hippocampus but not FCx. GRIN transcription in FCx correlated positively with SOC, but hippocampal GRIN transcription had negative correlation with SOC. The ratio of GRIN2A/GRIN2B transcription is known to increase during development but was lower in PRS mice. These results suggest that GRIN2A and GRIN2B transcript levels are modified in the hippocampus by PRS, leading to life-long deficits in social behavior. These data have some overlap with the molecular pathophysiology of schizophrenia. Similar to PRS in mice, schizophrenia, has been associated with social withdrawal, with increased GRIN2 expression in the hippocampus, and reduced GRIN2A/GRIN2B expression ratios in the hippocampus. These findings suggest that PRS in mice may have construct validity as a preclinical model for antipsychotic drug development.

Prenatal restraint stress affects early neurobehavioral response and oxidative stress in mice pups

Prenatal stress (PS), in both humans and animals, presents a potential risk to the mother and her fetus throughout gestation. PS is always associated with physiological changes that alter embryonic development and predispose the individual to lifelong health problems, including susceptibility to mental illness. This study aims to identify the harmful effects of prenatal restraint stress (PRS), commonly employed to induce stress painlessly and without any lasting debilitation during gestation. This stress is applied to pregnant Swiss albino mice from E7.5 to delivery for three hours daily. Our results show that PS affects dams' weight gain during the gestational period; moreover, the PS dams prefer passive nursing, exhibit a lower percentage of licking and grooming, and impair other maternal behaviors, including nesting and pup retrieval. Concerning the offspring, this stress induces neurobehavioral impairments, including a significant increase in the time of recovery of the young stressed pups in the surface righting reflex, the latency to avoid the cliff in the cliff avoidance test, longer latencies to accomplish the task in negative geotaxis, and a lower score in swimming development. These alterations were accompanied by increased Malondialdehyde activity (MDA) at PND17 and 21 and downregulation of AchE activity in the whole brain of pups on postnatal days 7 and 9. These findings demonstrated that PS causes deleterious neurodevelopmental impairments that can alter various behaviors later in life.

Prospective associations of prenatal stress with child behavior: Moderation by the early childhood caregiving environment

Fetal exposure to prenatal stress can increase risk for psychopathology but postnatal caregiving may offset risk. This study tests whether maternal sensitivity and the home environment during early childhood modify associations of prenatal stress with offspring behavior in a sample of 127 mother-child pairs (n = 127). Mothers reported on perceived stress during pregnancy. Maternal sensitivity was rated by coders during a parent-child free play task when children were 4 years old. One year later, mothers reported on the home environment, child internalizing and externalizing behaviors, and children completed an assessment of inhibitory control. As hypothesized, the early childhood caregiving environment modified associations of prenatal stress with child behavior. Specifically, prenatal stress was associated with more internalizing behaviors at lower levels of maternal sensitivity and in home environments that were lower in emotional support and cognitive stimulation, but not at mean or higher levels. Furthermore, prenatal stress was associated with lower inhibitory control only at lower levels of maternal sensitivity, but not at higher levels. Maternal sensitivity and an emotionally supportive and cognitively stimulating home environment in early childhood may be important factors that mitigate risk for mental health problems among children exposed to prenatal stress.

Early morphological and neurochemical changes of the bed nucleus of stria terminalis (BNST) in gestational protein-restricted male offspring

BACKGROUND

The bed nucleus of the stria terminalis (BNST) is a structure with a peculiar neurochemical composition involved in modulating anxietylike behavior and fear.

AIM

The present study investigated the effects on the BNST neurochemical composition and neuronal structure in critical moments of the postnatal period in gestational protein-restricted male rats' offspring.

METHODS

Dams were maintained during the pregnancy on isocaloric rodent laboratory chow with standard protein content [NP, 17%] or low protein content [LP, 6%]. BNST from male NP and age-matched LP offspring was studied using the isotropic fractionator method, Neuronal 3D reconstruction, dendritic-tree analysis, blotting analysis, and high-performance liquid chromatography.

RESULTS

Serum corticosterone levels were higher in male LP offspring than NP rats in 14-day-old offspring, without any difference in 7-day-old progeny. The BNST total cell number and anterodorsal BNST division volume in LP progeny were significantly reduced on the 14th postnatal day compared with NP offspring. The BNST HPLC analysis from 7 days-old LP revealed increased norepinephrine levels compared to NP progeny. The BNST blot analysis from 7-day-old LP revealed reduced levels of GR and BDNF associated with enhanced CRF1 expression compared to NP offspring. 14-day-old LP offspring showed reduced expression of MR and 5HT1A associated with decreased DOPAC and DOPA turnover levels relative to NP rats. In Conclusion, the BNST cellular and neurochemical changes may represent adaptation during development in response to elevated fetal exposure to maternal corticosteroid levels. In this way, gestational malnutrition alters the BNST content and structure and contributes to already-known behavioral changes.

Early establishment of chloride homeostasis in CRH neurons is altered by prenatal stress leading to fetal HPA axis dysregulation

Corticotropin-releasing hormone (CRH) neurons play an important role in the regulation of neuroendocrine responses to stress. The excitability of CRH neurons is regulated by inhibitory GABAergic inputs. However, it is unclear when GABAergic regulation of CRH neurons is established during fetal brain development. Furthermore, the exact progression of the developmental shift of GABA action from depolarization to hyperpolarization remains unelucidated. Considering the importance of CRH neuron function in subsequent hypothalamic-pituitary-adrenal (HPA) axis regulation during this critical phase of development, we investigated the ontogeny of GABAergic inputs to CRH neurons and consequent development of chloride homeostasis. Both CRH neuron soma in the paraventricular nucleus (PVN) and axons projecting to the median eminence could be identified at embryonic day 15 (E15). Using acute slices containing the PVN of CRF-VenusΔNeo mice, gramicidin perforated-patch clamp-recordings of CRH neurons at E15, postnatal day 0 (P0), and P7 were performed to evaluate the developmental shift of GABA action. The equilibrium potential of GABA (EGABA) was similar between E15 and P0 and showed a further hyperpolarizing shift between P0 and P7 that was comparable to EGABA values in adult CRH neurons. GABA primarily acted as an inhibitory signal at E15 and KCC2 expression was detected in CRH neurons at this age. Activation of the HPA axis has been proposed as the primary mechanism through which prenatal maternal stress shapes fetal development and subsequent long-term disease risk. We therefore examined the impact of maternal food restriction stress on the development of chloride homeostasis in CRH neurons. We observed a depolarization shift of EGABA in CRH neurons of pups exposed to maternal food restriction stress. These results suggest that Cl- homeostasis in early developmental CRH neurons attains mature intracellular Cl- levels, GABA acts primarily as inhibitory, and CRH neurons mature and function early compared with neurons in other brain regions, such as the cortex and hippocampus. Maternal food restriction stress alters chloride homeostasis in CRH neurons of pups, reducing their inhibitory control by GABA. This may contribute to increased CRH neuron activity and cause activation of the HPA axis in pups.

Developmental Neuroendocrinology of Early-Life Stress: Impact on Child Development and Behavior

Our internal balance, or homeostasis, is threatened or perceived as threatened by stressful stimuli, the stressors. The stress system is a highly conserved system that adjusts homeostasis to the resting state. Through the concurrent activation of the hypothalamic-pituitary-adrenal axis and the locus coeruleus/norepinephrine-autonomic nervous systems, the stress system provides the appropriate physical and behavioral responses, collectively termed as "stress response", to restore homeostasis. If the stress response is prolonged, excessive or even inadequate, several acute or chronic stress-related pathologic conditions may develop in childhood, adolescence and adult life. On the other hand, earlylife exposure to stressors has been recognized as a major contributing factor underlying the pathogenesis of non-communicable disorders, including neurodevelopmental disorders. Accumulating evidence suggests that early-life stress has been associated with an increased risk for attention deficit hyperactivity disorder and autism spectrum disorder in the offspring, although findings are still controversial. Nevertheless, at the molecular level, early-life stressors alter the chemical structure of cytosines located in the regulatory regions of genes, mostly through the addition of methyl groups. These epigenetic modifications result in the suppression of gene expression without changing the DNA sequence. In addition to DNA methylation, several lines of evidence support the role of non-coding RNAs in the evolving field of epigenetics. In this review article, we present the anatomical and functional components of the stress system, discuss the proper, in terms of quality and quantity, stress response, and provide an update on the impact of early-life stress on child development and behavior.

Genomic variation in neurons

Neurons born during the fetal period have extreme longevity and survive until the death of the individual because the human brain has highly limited tissue regeneration. The brain is comprised of an enormous variety of neurons each exhibiting different morphological and physiological characteristics and recent studies have further reported variations in their genome including chromosomal abnormalities, copy number variations, and single nucleotide mutations. During the early stages of brain development, the increasing number of neurons generated at high speeds has been proposed to lead to chromosomal instability. Additionally, mutations in the neuronal genome can occur in the mature brain. This observed genomic mosaicism in the brain can be produced by multiple endogenous and environmental factors and careful analyses of these observed variations in the neuronal genome remain central for our understanding of the genetic basis of neurological disorders.

Minireview: Glucocorticoid-Leptin Crosstalk: Role of Glucocorticoid-Leptin Counterregulation in Metabolic Homeostasis and Normal Development

Glucocorticoids and leptin are two important hormones that regulate metabolic homeostasis by controlling appetite and energy expenditure in adult mammals. Also, glucocorticoids and leptin strongly counterregulate each other, such that chronic stress-induced glucocorticoids upregulate the production of leptin and leptin suppresses glucocorticoid production directly via action on endocrine organs and indirectly via action on food intake. Altered glucocorticoid or leptin levels during development can impair organ development and increase the risk of chronic diseases in adults, but there are limited studies depicting the significance of glucocorticoid-leptin interaction during development and its impact on developmental programming. In mammals, leptin-induced suppression of glucocorticoid production is critical during development, where leptin prevents stress-induced glucocorticoid production by inducing a period of short-hyporesponsiveness when the adrenal glands fail to respond to certain mild to moderate stressors. Conversely, reduced or absent leptin signaling increases glucocorticoid levels beyond what is appropriate for normal organogenesis. The counterregulatory interactions between leptin and glucocorticoids suggest the potential significant involvement of leptin in disorders that occur from stress during development.

Atypical brain structure and function in young adults exposed to disaster-related prenatal maternal stress: Project Ice Storm

Studies have shown that prenatal maternal stress (PNMS) affects brain structure and function in childhood. However, less research has examined whether PNMS effects on brain structure and function extend to young adulthood. We recruited women who were pregnant during or within 3 months following the 1998 Quebec ice storm, assessed their PNMS, and prospectively followed-up their children. T1-weighted magnetic resonance imaging (MRI) and resting-state functional MRI were obtained from 19-year-old young adults with (n = 39) and without (n = 65) prenatal exposure to the ice storm. We examined between-group differences in gray matter volume (GMV), surface area (SA), and cortical thickness (CT). We used the brain regions showing between-group GMV differences as seeds to compare between-group functional connectivity. Within the Ice Storm group, we examined (1) associations between PNMS and the atypical GMV, SA, CT, and functional connectivity, and (2) moderation by timing of exposure. Primarily, we found that, compared to Controls, the Ice Storm youth had larger GMV and higher functional connectivity of the anterior cingulate cortex, the precuneus, the left occipital pole, and the right hippocampus; they also had larger CT, but not SA, of the left occipital pole. Within the Ice Storm group, maternal subjective distress during preconception and mid-to-late pregnancy was associated with atypical left occipital pole CT. These results suggest the long-lasting impact of disaster-related PNMS on child brain structure and functional connectivity. Our study also indicates timing-specific effects of the subjective aspect of PNMS on occipital thickness.

Impact of the trait anxiety during pregnancy on birth weight: an observational cohort study

To explore the effects of antenatal anxiety on fetal growth an observational cohort study was performed, including a cohort of 204 women with singleton pregnancies during the strict lockdown of the COVID-19 pandemic in 2020. Psychosocial factors, maternal demographics, obstetric outcomes, social support (Medical Outcomes Study Social Support Survey, MOS-SSS), and symptoms of anxiety (State-Trait Anxiety Inventory, STAIs and STAIt) and depression (Edinburgh Postpartum Depression Scale, EPDS) were studied as potential predictors of low birth weight. Main outcome measures were birth weight, head circumference and length. Results showed a negative correlation between STAIt score (trait anxiety) and birth weight percentile (r = -0.228, p = .047). In the univariate linear regression analysis, a lower maternal weight and BMI before pregnancy, parity, increased STAIt score and preterm birth below 37 weeks of gestation (p = .008, p = .015, p = .028, p = .047 and p = .022, respectively) were identified as predictive risk factors for low birth weight, whereas in the multivariate lineal regression analysis only a lower maternal weight before pregnancy and an increased STAIt score were independent predictors for low birth weight (p = .020, p = .049, respectively). To conclude, anxiety during pregnancy impacts birth weight, and specifically the trait anxiety, is a predictor for low birth weight.

Microbiota-gut-brain axis drives overeating disorders

Overeating disorders (ODs), usually stemming from dieting history and stress, remain a pervasive issue in contemporary society, with the pathological mechanisms largely unresolved. Here, we show that alterations in intestinal microbiota are responsible for the excessive intake of palatable foods in OD mice and patients with bulimia nervosa (BN). Stress combined with a history of dieting causes significant changes in the microbiota and the intestinal metabolism, which disinhibit the vagus nerve terminals in the gut and thereby lead to a subsequent hyperactivation of the gut-brain axis passing through the vagus, the solitary tract nucleus, and the paraventricular nucleus of the thalamus. The transplantation of a probiotic Faecalibacterium prausnitzii or dietary supplement of key metabolites restores the activity of the gut-to-brain pathway and thereby alleviates the OD symptoms. Thus, our study delineates how the microbiota-gut-brain axis mediates energy balance, unveils the underlying pathogenesis of the OD, and provides potential therapeutic strategies.

Increases in maternal depressive symptoms during pregnancy and infant cortisol reactivity: Mediation by placental corticotropin-releasing hormone

BACKGROUND

Maternal depressive symptoms in pregnancy may affect offspring health through prenatal programming of the hypothalamic-pituitary-adrenal (HPA) axis. The biological mechanisms that explain the associations between maternal prenatal depressive symptoms and offspring HPA axis regulation are not yet clear. This pre-registered investigation examines whether patterns of maternal depressive symptoms in pregnancy are associated with infant cortisol reactivity and whether this association is mediated by changes in placental corticotropin-releasing hormone (pCRH).

METHOD

A sample of 174 pregnant women completed assessments in early, mid, and late pregnancy that included standardized measures of depressive symptoms and blood samples for pCRH. Infant cortisol reactivity was assessed at 1 and 6 months of age.

RESULTS

Greater increases in maternal depressive symptoms in pregnancy were associated with higher cortisol infant cortisol reactivity at 1 and 6 months. Greater increases in maternal depressive symptoms in pregnancy were associated with greater increases in pCRH from early to late pregnancy which in turn were associated with higher infant cortisol reactivity.

CONCLUSIONS

Increases in maternal depressive symptoms and pCRH over pregnancy may contribute to higher infant cortisol reactivity. These findings help to elucidate the prenatal biopsychosocial processes contributing to offspring HPA axis regulation early in development.

Environmental modifications to rehabilitate social behavior deficits after acquired brain injury: What is the evidence?

Social behavior deficits are a common, debilitating consequence of traumatic brain injury and stroke, particularly when sustained during childhood. Numerous factors influence the manifestation of social problems after acquired brain injuries, raising the question of whether environmental manipulations can minimize or prevent such deficits. Here, we examine both clinical and preclinical evidence addressing this question, with a particular focus on environmental enrichment paradigms and differing housing conditions. We aimed to understand whether environmental manipulations can ameliorate injury-induced social behavior deficits. In summary, promising data from experimental models supports a beneficial role of environmental enrichment on social behavior. However, limited studies have considered social outcomes in the chronic setting, and few studies have addressed the social context specifically as an important component of the post-injury environment. Clinically, limited high-caliber evidence supports the use of specific interventions for social deficits after acquired brain injuries. An improved understanding of how the post-injury environment interacts with the injured brain, particularly during development, is needed to validate the implementation of rehabilitative interventions that involve manipulating an individuals' environment.

Lifelong effects of prenatal and early postnatal stress on the hippocampus, amygdala, and psychological states of Holocaust survivors

This study focuses on hippocampal and amygdala volume, seed-based connectivity, and psychological traits of Holocaust survivors who experienced stress during prenatal and early postnatal development. We investigated people who lived in Central Europe during the Holocaust and who, as Jews, were in imminent danger. The group who experienced stress during their prenatal development and early postnatal (PreP) period (n = 11) were compared with a group who experienced Holocaust-related stress later in their lives: in late childhood, adolescence, and early adulthood (ChA) (n = 21). The results of volumetry analysis showed significantly lower volumes of both hippocampi and the right amygdala in the PreP group. Seed-based connectivity analysis revealed increased connectivity from the seed in the right amygdala to the middle and posterior cingulate cortex, caudate, and inferior left frontal operculum in the PreP group. Psychological testing found higher levels of traumatic stress symptoms (TCS-40) and lower levels of well-being (SOS-10) in the PreP group than in the ChA group. The results of our study demonstrate that extreme stress experienced during prenatal and early postnatal life has a profound lifelong impact on the hippocampus and amygdala and on several psychological characteristics.

Fine and gross motor skills in 7-10 years old Indian children exposed to a natural disaster during early development

Fetal life and infancy are extremely sensitive to adverse environmental conditions. This study aimed to assess the effect of exposure to a natural disaster (cyclone Aila) in utero or during infancy on fine and gross motor functions in preadolescent Indian children. The study was conducted in West Bengal, India, and included approximately 700 children (7-10 years old) who were prenatally or postnatally exposed to cyclone Aila and a nonaffected group. Anthropometric measures included height, weight, and birthweight. Socioeconomic status was based on parental education, family size, and income. Motor functions were assessed using the short form of Bruininks-Oseretsky Test of Motor Proficiency (BOT-2). Statistical analyses included, for example, generalized linear models. There were no differences in motor functions relative to the timing of the exposure (trimester) during pregnancy. Compared to the controls, prenatal Aila exposure resulted in poorer performance in all BOT-2 subtests, except for fine motor precision, strength, and balance (the last in boys), while postnatal Aila exposure, compared to the controls, resulted in poorer performance in manual dexterity, bilateral coordination, balance (girls only), and speed and agility. Early life exposure to a natural disaster has long-term adverse effect on motor proficiency in children. By inference, the welfare of pregnant women and infants should be of particular concern for emergency and health services during an environmental cataclysm.

Parent-child interactions in early life mediating association between prenatal maternal stress and autistic-like behaviors among preschoolers

A range of studies have shown that prenatal maternal stress (PNMS) exposure is associated with offspring autistic-like behaviors, however the potential pathways remain unexplored. This study aimed to evaluate the mediating role of parent-child interactions in early life in the association between PNMS exposure and preschoolers' autistic-like behaviors. Data from 65,928 child-parent dyads were obtained via a primary caregiver-reported questionnaire administered as part of the Longhua Child Cohort Study. To strengthen confidence in the reliability of the results, the analyses were initially conducted on a random selection of 70% of the total sample, and then validated on the remaining 30% of the sample. Analysis of covariance and multiple linear models were employed to estimate the associations between PNMS exposure, parent-child interactions in early life, and children's autistic-like behaviors. The results showed that PNMS exposure was positively associated with the presence of autistic-like behaviors at preschool age. The total indirect effect of the frequency of positive parent-child interactions in early life accounted for 9.69% or 8.99% of the variance of the association. Our findings indicate that parent-child interactions in early life might function as potential mediators of the association between PNMS and the increased risk of offspring autistic-like behaviors.

Coping styles vary with species' sociality and life history: A systematic review and meta-regression analysis

Despite a long history of animal studies investigating coping styles, the causal connections between behavior and stress physiology remain unclear. Consistency across taxa in effect sizes would support the idea of a direct causal link maintained by either functional or developmental dependencies. Alternatively, lack of consistency would suggest coping styles are evolutionarily labile. Here, we investigated correlations between personality traits and baseline and stress-induced glucocorticoid levels using a systematic review and meta-analysis. Most personality traits did not consistently vary with either baseline or stress-induced glucocorticoids. Only aggression and sociability showed a consistent negative correlation with baseline glucocorticoids. We found that life history variation affected the relationship between stress-induced glucocorticoid levels and personality traits, especially anxiety and aggression. The relationship between anxiety and baseline glucocorticoids depended on species' sociality with solitary species showing more positive effect sizes. Thus, integration between behavioral and physiological traits depends on species' sociality and life history and suggests high evolutionary lability of coping styles.

Estrogens, age, and, neonatal stress: panic disorders and novel views on the contribution of non-medullary structures to respiratory control and CO2 responses

CO₂ is a fundamental component of living matter. This chemical signal requires close monitoring to ensure proper match between metabolic production and elimination by lung ventilation. Besides ventilatory adjustments, CO₂ can also trigger innate behavioral and physiological responses associated with fear and escape but the changes in brain CO₂/pH required to induce ventilatory adjustments are generally lower than those evoking fear and escape. However, for patients suffering from panic disorder (PD), the thresholds for CO₂-evoked hyperventilation, fear and escape are reduced and the magnitude of those reactions are excessive. To explain these clinical observations, Klein proposed the false suffocation alarm hypothesis which states that many spontaneous panics occur when the brain's suffocation monitor erroneously signals a lack of useful air, thereby maladaptively triggering an evolved suffocation alarm system. After 30 years of basic and clinical research, it is now well established that anomalies in respiratory control (including the CO₂ sensing system) are key to PD. Here, we explore how a stress-related affective disorder such as PD can disrupt respiratory control. We discuss rodent models of PD as the concepts emerging from this research has influenced our comprehension of the CO₂ chemosensitivity network, especially structure that are not located in the medulla, and how factors such as stress and biological sex modulate its functionality. Thus, elucidating why hormonal fluctuations can lead to excessive responsiveness to CO₂ offers a unique opportunity to gain insights into the neuroendocrine mechanisms regulating this key aspect of respiratory control and the pathophysiology of respiratory manifestations of PD.

Effects of maternal social isolation on adult rodent offspring cognition

Prenatal experiences can influence offspring physiology and behaviour through the lifespan. Various forms of prenatal stress impair adult learning and memory function and can lead to increased occurrence of anxiety and depression. Clinical work suggests that prenatal stress and maternal depression lead to similar outcomes in children and adolescents, however the long-term effects of maternal depression are less established, particularly in well controlled animal models. Social isolation is common in depressed individuals and during the recent COVID-19 pandemic. Accordingly, for this study we were interested in the effects of maternal stress induced via social isolation on adult offspring cognitive functions including spatial, stimulus-response, and emotional learning and memory that are mediated by different networks centered on the hippocampus, dorsal striatum, and amygdala, respectively. Tasks included a discriminative contextual fear conditioning task and cue-place water task. Pregnant dams in the social isolation group were single housed prior to and throughout gestation. Once offspring reached adulthood the male offspring were trained on a contextual fear conditioning task in which rats were trained to associate one of two contexts with an aversive stimulus and the opposing context remained neutral. Afterwards a cue-place water task was performed during which they were required to navigate to both a visible and invisible platform. Fear conditioning results revealed that the adult offspring of socially isolated mothers, but not controls, were impaired in associating a specific context with a fear-inducing stimulus as assessed by conditioned freezing and avoidance. Results from the water task indicate that adult offspring of mothers that were socially isolated showed place learning deficits but not stimulus-response habit learning on the same task. These cognitive impairments, in the offspring of socially isolated dams, occurred in the absence of maternal elevated stress hormone levels, anxiety, or altered mothering. Some evidence suggested that maternal blood-glucose levels were altered particularly during gestation. Our results provide further support for the idea that learning and memory networks, centered on the amygdala and hippocampus are particularly susceptible to the negative impacts of maternal social isolation and these effects can occur without elevated glucocorticoid levels associated with other forms of prenatal stress.

A framework for testing pathways from prenatal stress-responsive hormones to cardiovascular disease risk

Cardiovascular disease (CVD) is a leading cause of death globally, with the prevalence projected to keep rising. Risk factors for adult CVD emerge at least as early as the prenatal period. Alterations in stress-responsive hormones in the prenatal period are hypothesized to contribute to CVD in adulthood, but little is known about relations between prenatal stress-responsive hormones and early precursors of CVD, such as cardiometabolic risk and health behaviors. The current review presents a theoretical model of the relation between prenatal stress-responsive hormones and adult CVD through cardiometabolic risk markers (e.g., rapid catch-up growth, high BMI/adiposity, high blood pressure, and altered blood glucose, lipids, and metabolic hormones) and health behaviors (e.g., substance use, poor sleep, poor diet and eating behaviors, and low physical activity levels). Emerging evidence in human and non-human animal literatures suggest that altered stress-responsive hormones during gestation predict higher cardiometabolic risk and poorer health behaviors in offspring. This review additionally highlights limitations of the current literature (e.g., lack of racial/ethnic diversity, lack of examination of sex differences), and discusses future directions for this promising area of research.

Annual Research Review: Emotion processing in offspring of mothers with depression diagnoses - a systematic review of neural and physiological research

BACKGROUND

Theories of the intergenerational transmission of depression emphasize alterations in emotion processing among offspring of depressed mothers as a key risk mechanism, raising questions about biological processes contributing to these alterations. The objective of this systematic annual research review was to examine and integrate studies of the associations between maternal depression diagnoses and offspring's emotion processing from birth through adolescence across biological measures including autonomic psychophysiology, electroencephalography (EEG), magnetoencephalography (MEG), event-related potentials (ERP), and structural and functional magnetic resonance imaging (MRI).

METHODS

The review was conducted in accordance with the PRISMA 2020 standards. A systematic search was conducted in PsycInfo and PubMed in 2022 for studies that included, 1) mothers with and without DSM-defined depressive disorders assessed via a clinical or diagnostic interview, and 2) measures of offspring emotion processing assessed at the psychophysiological or neural level between birth and 18 years of age.

RESULTS

Findings from 64 studies indicated that young offspring of mothers with depression histories exhibit heightened corticolimbic activation to negative emotional stimuli, reduced left frontal brain activation, and reduced ERP and mesocorticolimbic responses to reward cues compared to offspring of never-depressed mothers. Further, activation of resting-state networks involved in affective processing differentiate offspring of depressed relative to nondepressed mothers. Some of these alterations were only apparent among youth of depressed mothers exposed to negative environmental contexts or exhibiting current emotional problems. Further, some of these patterns were observable in infancy, reflecting very early emerging vulnerabilities.

CONCLUSIONS

This systematic review provides evidence that maternal depression is associated with alterations in emotion processing across several biological units of analysis in offspring. We present a preliminary conceptual model of the role of deficient emotion processing in pathways from maternal depression to offspring psychopathology and discuss future research avenues addressing limitations of the existing research and clinical implications.

Ameliorating age-dependent effects of resveratrol on VPA-induced social impairments and anxiety-like behaviors in a rat model of Neurodevelopmental Disorder

Although anxiety disorders, as well as difficulties in social interaction, are documented in children with autism spectrum disorder (ASD) as a neurodevelopmental disorder, the effectiveness of potential therapeutic procedures considering age and sex differences is under serious discussion. The present study aimed to investigate the effect of resveratrol (RSV) on anxiety-like behaviors and social interaction in juvenile and adult rats of both sex in a valproic acid (VPA)-induced autistic-like model. Prenatal exposure to VPA was associated with increased anxiety, also causing a significant reduction in social interaction in juvenile male subjects. Further administration of RSV attenuated VPA-induced anxiety symptoms in both sexes of adult animals and significantly increased the sociability index in male and female juvenile rats. Taken together, it can be concluded that treatment with RSV can attenuate some of the harsh effects of VPA. This treatment was especially effective on anxiety-like traits in adult subjects of both sexes regarding their performance in open field and EPM. We encourage future research to consider the sex and age-specific mechanisms behind the RSV treatment in the prenatal VPA model of autism.

Early Life Stress, Hormones, and Neurodevelopmental Disorders

BACKGROUND

Early life stress (ELS) describes a broad spectrum of adverse and stressful prenatal events, namely, prenatal maternal stress (PMS), or early postnatal events, which can have detrimental long-term influences on the physiology, cognition, and behavior of an individual. There is abundant evidence indicating that ELS exerts its lasting effects on the physical and mental health of the individual, likely acting through a number of mediating mechanisms, including the disruption of developmental programming of the fetus. Neurodevelopmental disorders (NDDs), for example, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), are a group of conditions that typically manifest during infancy, childhood, or adolescence and are characterized by developmental deficits in various domains.

SUMMARY

The scope of the current mini-review is to provide an up-to-date summary of the findings regarding the association of ELS and NDDs and the possible hormonal mechanisms through which PMS exerts its impact on neurodevelopment. We focus on the available evidence regarding children and adolescents diagnosed with ADHD or ASD. ELS exposure during developmental vulnerability windows may increase the risk for either subclinical neuropsychological alterations or clinical conditions, such as NDDs. In fact, a large body of evidence underlies the association of ELS exposure and increased risk for NDDs in the offspring.

KEY MESSAGES

The majority of data suggest that ELS, including PMS, may be associated with ADHD and ASD in the offspring, although there is no consensus regarding the critical developmental periods. Carefully controlled prospective studies are needed to determine the possible causal processes and mechanisms underlying the association of ELS and NDDs.

Prenatal maternal stress and the severity of autism spectrum disorder: A cross-sectional study

Autism spectrum disorder (ASD) is a neurodevelopmental disorder linked to several genetic and environmental factors including antenatal stress. Hence, we aimed to examine whether a mother's stress during pregnancy is associated with the severity of autism spectrum disorder in children. The study was conducted with 459 mothers of children with autism (aged 2-14 years) who were attending rehabilitation and educational centers in the two major cities of Makkah and Jeddah in Saudi Arabia. Environmental factors, consanguinity, and ASD family history were assessed using a validated questionnaire. The Prenatal Life Events Scale questionnaire was used to assess whether the mothers were exposed to stress during pregnancy. Two models of ordinal regression analysis were conducted including gender, child age maternal age, parental age, maternal education, parental education, income nicotine exposure, mother taking medication during pregnancy, family history of ASD, gestation, consanguinity, exposure of prenatal life events (in model 1), and severity of prenatal life events (in model 2). Family history of ASD showed a statistically significant association with the severity of ASD in both regression models (p = .015, odds ratio [OR]: 4.261 in Model 1, and p = .014, OR: 4.901 in model 2). In model 2, the moderate severity prenatal life events showed higher statistically significant adjusted odds ratio for ASD severity compared to no stress (p = .031; OR: 3.82). Within the limitations of this study, prenatal stressors showed some potential contribution to ASD severity. Family history of ASD was the only factor that showed a persistent association with ASD severity. A study that assesses the effect of COVID-19 stress on ASD prevalence and severity is recommended.

Prenatal maternal depression predicts neural maturation and negative emotion in infants

Despite widespread acceptance that prenatal symptoms of depression in mothers are detrimental to infants' long-term emotional and cognitive development, little is known about the mechanisms that may integrate outcomes across these domains. Rooted in the integrative perspective that emotional development is grounded in developing cognitive processes, we hypothesized that prenatal symptoms of depression in mothers would be associated with delays in neural maturation that support sociocognitive function in infants, leading to more problematic behaviors. We used a prospective longitudinal study of mothers (N = 92) and their infants to test whether self-reported symptoms of depression in mothers during the second and third trimesters were associated with neural development and infant outcomes at 4 months of age. While controlling for postpartum symptoms of depression, more prenatal symptoms of depression in mothers predicted less neural maturation in the parietal region of 4-month-old infants. Less neural maturation, in turn, was associated with greater infant negativity, suggesting neural maturation as a putative mechanism linking maternal symptoms of depression with infant outcomes. Differences in neural regions and developmental timing are also discussed.

Moderate prenatal alcohol exposure produces sex-specific social impairments and attenuates prelimbic excitability and amygdala-cortex modulation of adult social behaviour

Lifelong social impairments are common in individuals with prenatal alcohol exposure (PAE), and preclinical studies have identified gestational day (G)12 as a vulnerable timepoint for producing social deficits following binge-level PAE. While moderate (m)PAE also produces social impairments, the long-term neuroadaptations underlying them are poorly understood. Activity of the projection from the basolateral amygdala to the prelimbic cortex (BLA → PL) leads to social avoidance, and the PL is implicated in negative social behaviours, making each of these potential candidates for the neuroadaptations underlying mPAE-induced social impairments. To examine this, we first established that G12 mPAE produced sex-specific social impairments lasting into adulthood in Sprague-Dawley rats. We then chemogenetically inhibited the BLA → PL using clozapine N-oxide (CNO) during adult social testing. This revealed that CNO reduced social investigation in control males but had no effect on mPAE males or females of either exposure, indicating that mPAE attenuated the role of this projection in regulating male social behaviour and highlighting one potential mechanism by which mPAE affects male social behaviour more severely. Using whole-cell electrophysiology, we also examined mPAE-induced changes to PL pyramidal cell physiology and determined that mPAE reduced cell excitability, likely due to increased suppression by inhibitory interneurons. Overall, this work identified two mPAE-induced neuroadaptations that last into adulthood and that may underlie the sex-specific vulnerability to mPAE-induced social impairments. Future research is necessary to expand upon how these circuits modulate both normal and pathological social behaviours and to identify sex-specific mechanisms, leading to differential vulnerability in males and females.

Failure of motor function-A Developmental Embodiment Research perspective on the systemic effects of stress

Humans are capable to skillfully perform a huge variety of complex movements seemingly effortless and to flexibly adjust movement execution to ever-changing environmental conditions, often without apparent differences in the movement outcome. This impressive ability has sparked scientific interest in the mechanisms underlying movement execution for decades. In this perspective article, we argue that investigating the processes and mechanisms leading to failure of motor functions is a fruitful approach to advance the field of human motor neuroscience and beyond. The study of failure of motor function in specific populations (patient groups, skilled experts) has already provided tremendous insight in the systemic characteristics and multi-level functional dependencies of movement execution. However, particularly the transient failure of function in everyday motor actions remains a blind spot. Coming from the perspective of Developmental Embodiment Research, we argue that the integration of a developmental embodiment and lifespan perspective with existing systemic and multi-level methodological approaches of failure of function analyses provides an integrative, interdisciplinary framework, which will allow us to overcome this shortcoming. We further suggest that stress-induced failure of motor function situations might represent a promising starting point for this endeavor. Identifying the involved cross-level functional dependencies of acute and chronic stress on transient and persistent motor functioning would further advance our knowledge on the mechanisms underlying movement execution, and would allow to identify targets for intervention and prevention across the whole spectrum of motor function and failure.

Environmental Risk Factors and Cognitive Outcomes in Psychosis: Pre-, Perinatal, and Early Life Adversity

Risk for psychosis begins to accumulate as early as the fetal period through exposure to obstetric complications like fetal hypoxia, maternal stress, and prenatal infection. Stressors in the postnatal period, such as childhood trauma, peer victimization, and neighborhood-level adversity, further increase susceptibility for psychosis. Cognitive difficulties are among the first symptoms to emerge in individuals who go on to develop a psychotic disorder. We review the relationship between pre-, perinatal, and early childhood adversities and cognitive outcomes in individuals with psychosis. Current evidence shows that the aforementioned environmental risk factors may be linked to lower overall intelligence and executive dysfunction, beginning in the premorbid period and persisting into adulthood in individuals with psychosis. It is likely that early life stress contributes to cognitive difficulties in psychosis through dysregulation of the body's response to stress, causing changes such as increased cortisol levels and chronic immune activation, which can negatively impact neurodevelopment. Intersectional aspects of identity (e.g., sex/gender, race/ethnicity), as well as gene-environment interactions, likely inform the developmental cascade to cognitive difficulties throughout the course of psychotic disorders and are reviewed below. Prospective studies of birth cohorts will serve to further clarify the relationship between early-life environmental risk factors and cognitive outcomes in the developmental course of psychotic disorders. Specific methodological recommendations are provided for future research.

FAM3A Ameliorates Brain Impairment Induced by Hypoxia-Ischemia in Neonatal Rat

Hypoxia-ischemia (HI) during crucial periods of brain formation can lead to changes in brain morphology, propagation of neuronal stimuli, and permanent neurodevelopmental impairment, which can have profound effects on cognitive function later in life. FAM3A, a subgroup of family with sequence similarity 3 (FAM3) gene family, is ubiquitously expressed in almost all cells. Overexpression of FAM3A has been evidenced to reduce hyperglycemia via the PI3K/Akt signaling pathway and protect mitochondrial function in neuronal HT22 cells. This study aims to evaluate the protective role of FAM3A in HI-induced brain impairment. Experimentally, maternal rats underwent uterine artery bilateral ligation to induce neonatal HI on day 14 of gestation. At 6 weeks of age, cognitive development assessments including NSS, wire grip, and water maze were carried out. The animals were then sacrificed to assess cerebral mitochondrial function as well as levels of FAM3A, TNF-α and IFN-γ. Results suggest that HI significantly reduced FAM3A expression in rat brain tissues, and that overexpression of FAM3A through lentiviral transduction effectively improved cognitive and motor functions in HI rats as reflected by improved NSS evaluation, cerebral water content, limb strength, as well as spatial learning and memory. At the molecular level, overexpression of FAM3A was able to promote ATP production, balance mitochondrial membrane potential, and reduce levels of pro-inflammatory cytokines TNF-α and IFN-γ. We conclude that FAM3A overexpression may have a protective effect on neuron morphology, cerebral mitochondrial as well as cognitive function. Created with Biorender.com.

Prenatal Stress and the Developing Brain: Postnatal Environments Promoting Resilience

Heightened maternal stress during pregnancy is associated with atypical brain development and an elevated risk for psychopathology in offspring. Supportive environments during early postnatal life may promote brain development and reverse atypical developmental trajectories induced by prenatal stress. We reviewed studies focused on the role of key early environmental factors in moderating associations between prenatal stress exposure and infant brain and neurocognitive outcomes. Specifically, we focused on the associations between parental caregiving quality, environmental enrichment, social support, and socioeconomic status with infant brain and neurocognitive outcomes. We examined the evidence that these factors may moderate the effects of prenatal stress on the developing brain. Complementing findings from translational models, human research suggests that high-quality early postnatal environments are associated with indices of infant neurodevelopment that have also been associated with prenatal stress, such as hippocampal volume and frontolimbic connectivity. Human studies also suggest that maternal sensitivity and higher socioeconomic status may attenuate the effects of prenatal stress on established neurocognitive and neuroendocrine mediators of risk for psychopathology, such as hypothalamic-pituitary-adrenal axis functioning. Biological pathways that may underlie the effects of positive early environments on the infant brain, including the epigenome, oxytocin, and inflammation, are also discussed. Future research in humans should examine resilience-promoting processes in relation to infant brain development using large sample sizes and longitudinal designs. The findings from this review could be incorporated into clinical models of risk and resilience during the perinatal period and used to design more effective early programs that reduce risk for psychopathology.

Maternal Distress during Pregnancy and the Postpartum Period: Underlying Mechanisms and Child's Developmental Outcomes-A Narrative Review

Maternal mental health may be considered a determining factor influencing fetal and child development. An essential factor with potentially negative consequences for a child's psychophysiological development is the presence of maternal distress during pregnancy and the postpartum period. The review is organized and presented to explore and describe the effects of anxiety, stress, and depression in pregnancy and the postpartum period on adverse child developmental outcomes. The neurobiology of maternal distress and the transmission mechanisms at the molecular level to the fetus and child are noted. In addition, the paper discusses the findings of longitudinal studies in which early child development is monitored concerning the presence of maternal distress in pregnancy and the postpartum period. This topic gained importance in the COVID-19 pandemic context, during which a higher frequency of maternal psychological disorders was observed. The need for further interdisciplinary research on the relationship between maternal mental health and fetal/child development was highlighted, especially on the biological mechanisms underlying the transmission of maternal distress to the (unborn) child, to achieve positive developmental outcomes and improve maternal and child well-being.

Pathways to depression: Dynamic associations between neural responses to appetitive cues in the environment, stress, and the development of illness

This review focuses on research my colleagues and I have conducted on etiological pathways to depression. Much of this work has focused on the measurement of neural responses to appetitive cues, using two event-related brain potential (ERP) components, the Late Positive Potential (LPP) and the Reward Positivity (RewP). Reductions in each of these components have been associated with current symptoms of depression, and in some cases have been shown to differentiate anxious from depressive phenotypes. In this review, I will describe three broad and related approaches we have taken in our research to address a series of interdependent issuess. The first attempts to understand different sources of variation in the LPP and RewP, and how these sources interact with one another. The second tries to identify whether variation in the processes measured by these ERP components might reflect a latent vulnerability to depression and its symptoms, that is evident prior to illness onset. And the third examines the possibility that the processes reflected in the LPP and RewP might play a mechanistic role in the development of depression.

Maternal Childhood Maltreatment Is Associated With Lower Infant Gray Matter Volume and Amygdala Volume During the First Two Years of Life

Background

Childhood maltreatment affects approximately 25% of the world's population. Importantly, the children of mothers who have been maltreated are at increased risk of behavioral problems. Thus, one important priority is to identify child neurobiological processes associated with maternal childhood maltreatment (MCM) that might contribute to such intergenerational transmission. This study assessed the impact of MCM on infant gray and white matter volumes and infant amygdala and hippocampal volumes during the first 2 years of life.

Methods

Fifty-seven mothers with 4-month-old infants were assessed for MCM, using both the brief Adverse Childhood Experiences screening questionnaire and the more detailed Maltreatment and Abuse Chronology of Exposure scale. A total of 58% had experienced childhood maltreatment. Between 4 and 24 months (age in months: mean = 12.28, SD = 5.99), under natural sleep, infants completed a magnetic resonance imaging scan using a 3T Siemens scanner. Total brain volume, gray matter volume, white matter volume, and amygdala and hippocampal volumes were extracted via automated segmentation.

Results

MCM on the Adverse Childhood Experiences and Maltreatment and Abuse Chronology of Exposure scales were associated with lower infant total brain volume and gray matter volume, with no moderation by infant age. However, infant age moderated the association between MCM and right amygdala volume, such that MCM was associated with lower volume at older ages.

Conclusions

MCM is associated with alterations in infant brain volumes, calling for further identification of the prenatal and postnatal mechanisms contributing to such intergenerational transmission. Furthermore, the brief Adverse Childhood Experiences questionnaire predicted these alterations, suggesting the potential utility of early screening for infant risk.

Birth of the blues: emotional sound processing in infants exposed to prenatal maternal depression

BACKGROUND

Offspring exposed to prenatal maternal depression (PMD) are vulnerable to depression across their lifespan. The underlying cause(s) for this elevated intergenerational risk is most likely complex. However, depression is underpinned by a dysfunctional frontal-limbic network, associated with core information processing biases (e.g. attending more to sad stimuli). Aberrations in this network might mediate transmission of this vulnerability in infants exposed to PMD. In this study, we aimed to explore the association between foetal exposure to PMD and frontal-limbic network function in infancy, hypothesising that, in response to emotional sounds, infants exposed to PMD would exhibit atypical activity in these regions, relative to those not exposed to PMD.

METHOD

We employed a novel functional magnetic resonance imaging sequence to compare brain function, whilst listening to emotional sounds, in 78 full-term infants (3-6 months of age) born to mothers with and without a diagnosis of PMD.

RESULTS

After exclusion of 19 datasets due to infants waking up, or moving excessively, we report between-group brain activity differences, between 29 infants exposed to PMD and 29 infants not exposed to PMD, occurring in temporal, striatal, amygdala/parahippocampal and frontal regions (p < 0.005). The offspring exposed to PMD exhibited a relative increase in activation to sad sounds and reduced (or unchanged) activation to happy sounds in frontal-limbic clusters.

CONCLUSIONS

Findings of a differential response to positive and negative valanced sounds by 3-6 months of age may have significant implications for our understanding of neural mechanisms that underpin the increased risk for later-life depression in this population.

Maternal-fetal stress and DNA methylation signatures in neonatal saliva: an epigenome-wide association study

BACKGROUND

Maternal stress before, during and after pregnancy has profound effects on the development and lifelong function of the infant's neurocognitive development. We hypothesized that the programming of the central nervous system (CNS), hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) induced by prenatal stress (PS) is reflected in electrophysiological and epigenetic biomarkers. In this study, we aimed to find noninvasive epigenetic biomarkers of PS in the newborn salivary DNA.

RESULTS

A total of 728 pregnant women were screened for stress exposure using Cohen Perceived Stress Scale (PSS), 164 women were enrolled, and 114 dyads were analyzed. Prenatal Distress Questionnaire (PDQ) was also administered to assess specific pregnancy worries. Transabdominal fetal electrocardiograms (taECG) were recorded to derive coupling between maternal and fetal heart rates resulting in a 'Fetal Stress Index' (FSI). Upon delivery, we collected maternal hair strands for cortisol measurements and newborn's saliva for epigenetic analyses. DNA was extracted from saliva samples, and DNA methylation was measured using EPIC BeadChip array (850 k CpG sites). Linear regression was used to identify associations between PSS/PDQ/FSI/Cortisol and DNA methylation. We found epigenome-wide significant associations for 5 CpG with PDQ and cortisol at FDR < 5%. Three CpGs were annotated to genes (Illumina Gene annotation file): YAP1, TOMM20 and CSMD1, and two CpGs were located approximately lay at 50 kb from SSBP4 and SCAMP1. In addition, two differentiated methylation regions (DMR) related to maternal stress measures PDQ and cortisol were found: DAXX and ARL4D.

CONCLUSIONS

Genes annotated to these CpGs were found to be involved in secretion and transportation, nuclear signaling, Hippo signaling pathways, apoptosis, intracellular trafficking and neuronal signaling. Moreover, some CpGs are annotated to genes related to autism, post-traumatic stress disorder (PTSD) and schizophrenia. However, our results should be viewed as hypothesis generating until replicated in a larger sample. Early assessment of such noninvasive PS biomarkers will allow timelier detection of babies at risk and a more effective allocation of resources for early intervention programs to improve child development. A biomarker-guided early intervention strategy is the first step in the prevention of future health problems, reducing their personal and societal impact.

Trans- and Multigenerational Maternal Social Isolation Stress Programs the Blood Plasma Metabolome in the F3 Generation

Metabolic risk factors are among the most common causes of noncommunicable diseases, and stress critically contributes to metabolic risk. In particular, social isolation during pregnancy may represent a salient stressor that affects offspring metabolic health, with potentially adverse consequences for future generations. Here, we used proton nuclear magnetic resonance (¹H NMR) spectroscopy to analyze the blood plasma metabolomes of the third filial (F3) generation of rats born to lineages that experienced either transgenerational or multigenerational maternal social isolation stress. We show that maternal social isolation induces distinct and robust metabolic profiles in the blood plasma of adult F3 offspring, which are characterized by critical switches in energy metabolism, such as upregulated formate and creatine phosphate metabolisms and downregulated glucose metabolism. Both trans- and multigenerational stress altered plasma metabolomic profiles in adult offspring when compared to controls. Social isolation stress increasingly affected pathways involved in energy metabolism and protein biosynthesis, particularly in branched-chain amino acid synthesis, the tricarboxylic acid cycle (lactate, citrate), muscle performance (alanine, creatine phosphate), and immunoregulation (serine, threonine). Levels of creatine phosphate, leucine, and isoleucine were associated with changes in anxiety-like behaviours in open field exploration. The findings reveal the metabolic underpinnings of epigenetically heritable diseases and suggest that even remote maternal social stress may become a risk factor for metabolic diseases, such as diabetes, and adverse mental health outcomes. Metabolomic signatures of transgenerational stress may aid in the risk prediction and early diagnosis of non-communicable diseases in precision medicine approaches.

Association between antenatal glucocorticoid exposure and the activity of the stress system, cognition, and behavior in 8- to 9-year-old children: A prospective observational study

INTRODUCTION

Glucocorticoid (GC) -induced fetal programming of the activity of the hypothalamus-pituitary-adrenal axis (HPAA) and its associated cognitive and behavioral consequences in later life have been well characterized in several animal species. However, information on humans is scarce. In this study, we examined HPAA activity markers and associated outcomes at 8 to 9 years of age among children prenatally exposed to GC for suspected preterm birth. Our hypothesis was that antenatal exposure to the betamethasone (BM) is associated with exacerbation of HPAA activity in childhood.

MATERIAL AND METHODS

Prospective observational study in 31 children whose mothers received single (n = 19) or multiple (n = 12) courses of BM for threatened preterm birth but born with normal weight appropriate for the gestational age (median 37+⁶  weeks of gestation) compared with 38 non-exposed, age-matched children. Primary end point was the activity of the HPAA in response to the Trier Social Stress Test. Secondary end points were changes in autonomic nervous system (ANS) activity, cognitive performance (IQ), attention-deficit/hyperactivity disorder (ADHD) symptoms, and electrocortical activity (EEG).

RESULTS

There was no statistically significant difference in HPAA activity markers between antenatal BM exposed and unexposed groups. ANS activity in BM-exposed children shifted towards a higher parasympathetic tone reflected by a higher overall high-frequency band power of heart rate variability. IQ scores were within normal limits for both groups; however, BM-exposed children had lower IQ scores than the unexposed group. BM-exposed group had marginally more ADHD core symptoms and increased electrocortical activity in the occipital brain region compared with controls. A monotonic dose-response relationship between BM exposure and activity of the ANS and IQ was estimated in post-hoc analyses.

CONCLUSIONS

Antenatal exposure to BM in the context of threatened preterm birth was not associated with changes in HPAA activity in childhood. However, BM exposure may be associated with changes in ANS activity. Antenatal GC prophylaxis is a valuable and often life-saving therapy, but its prescription may warrant a well-balanced risk-benefit assessment.

Acute and Protracted Prenatal Stress Produce Mood Disorder-Like and Ethanol Drinking Behaviors in Male and Female Adult Offspring

Background

Alcohol use disorder (AUD) is a complex and chronic relapsing brain disease, which is often co-morbid with psychiatric disorders such as anxiety and depression. AUD phenotypes differ in men and women. Although genetic factors play an important role in its pathophysiology, epidemiologic evidence suggests that during prenatal development, individuals are more vulnerable to the negative effects of environmental factors that may predispose them to AUD later in life. We explored the effects of prenatal stress on the development of AUD phenotypes as well as anxiety- and depression-like behaviors using rat model.

Methods

In this study, timed-pregnant Sprague Dawley dams were used. Dams in the control group were left undisturbed throughout gestation, whereas dams in stress groups were either subjected to protracted or acute restraint stress under bright light. At adulthood, the anxiety-like, ethanol drinking, and sucrose drinking behaviors were measured using the Light/Dark Box test and two-bottle free-choice procedure.

Results

Compared to the control group, both the male and female offspring in the stress groups exhibited anxiety-like behavior and consumed significantly higher amounts of ethanol in which the acute stress group demonstrated the higher ethanol preference. Moreover, male but not female offspring from the stress groups had decreased sucrose preferences.

Conclusion

These findings suggest that protracted and acute prenatal stress in late pregnancy can induce in anxiety-, depressive-like behaviors, and excessive ethanol intake in adult offspring.

The effect of oxytocin and an enriched environment on anxiety-like behaviour and corticosterone levels in a prenatally stressed febrile seizure rat model

Background

Febrile seizures (FS) are a neurological abnormality which occur following a fever that has resulted from a systemic infection and are characterised by convulsions. These convulsions occur due to abnormally increased signalling of interleukin-1 beta, resulting in increased neuronal hyper-excitability. Furthermore, exposure to prenatal stress has been shown to exacerbate seizure duration, elicit anxiety-like behaviour and corticosterone levels. Oxytocin is a neuropeptide with anxiolytic, social bonding, and stress regulation effects. Therefore, the aim of the study was to assess whether oxytocin can attenuate the anxiety-like behaviour and increased corticosterone in rat offspring exposed to prenatal stress and FS.

Method

Sprague Dawley rats were mated. On GND14, prenatal stress was induced on pregnant dams for 1 hr/7 days. On PND 14, rat pups were injected with lipopolysaccharide (LPS, 200 μg/kg, i.p.) followed 2.5 h later by an i.p. injection of kainic acid (KA, 1.75 mg/kg). Oxytocin (1 mg/kg) was induced via different routes (intraperitoneal or intranasal) as well an enriched environment between PND 22-26. The enriched environment included larger cages (1560 cm²) with only 4 pups per cage, compared to those groups not receiving enrichment (646 cm²), as well as cardboard rolls and plastic toys. On PND 27-33 the light/dark box and elevated plus maze were used to assess anxiety-like behaviour. On PND 34 all rats were euthanized using a sharp guillotine, trunk blood and hypothalamic tissue were collected for neurochemical analysis (ELISA kit).

Results

Our findings confirmed that exposure to both prenatal stress and febrile seizures resulted anxiety-like behaviour and significantly higher plasma corticosterone concentrations compared to their counterparts. Environmental enrichment was significantly effective in attenuating the increased basal corticosterone levels and anxiety-like behaviour seen in the prenatally stressed FS rat. Although direct administration of oxytocin showed higher significance in reducing corticosterone plasma levels when compared to the enriched environment. Furthermore, hypothalamic oxytocin levels were not significant in rat exposed to environmental enrichment while oxytocin treatment showed a significant effect when compared to their counterparts.

Conclusion

Therefore, oxytocin administration during early postnatal development shows great potential in reversing the effects of prenatal stress and its subsequent exacerbation of FS.

Vaginal Microbiota Diversity in Response to Lipopolysaccharide in Gilts Housed Under Three Housing Systems

The United Kingdom and European Union have banned crates for pregnant sows. However, animals are kept in a restrictive environment for up to four weeks after mating, leading to stress and different responses of the animals’ immune system. Here, we used vaginal flushing of gilts to investigate whether housing systems or an experimental inflammatory challenge with lipopolysaccharide (LPS) can modify the gilt vaginal microbiome. Alpha-diversity indices showed differences in the microbiota of gilts housed under different systems (q = 0.04). Shannon alpha-diversity richness was higher in gilts group-housed in pens than in gilts housed in crates (q = 0.035), but not higher than in other groups. The relative abundance of the operational taxonomic unit (OTU) (q < 0.05) revealed specific differences in housing systems before a LPS or saline (SAL control) challenge. We found different abundances in taxa of Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Proteobacteria in gilts housed in the different systems before challenge. After the LPS challenge, significant differences were detected in the relative abundance of OTUs (q < 0.05) for the LPS-challenged group compared with SAL animals for each housing system. The phylum Staphylococcus showed higher abundance among the LPS-challenged gilts than in SAL-challenged animals. Furthermore, Enterobacter was more abundant in the LPS-challenged gilts housed in crates than in SAL-challenged gilts housed in crates. Streptococcus suis, Conchiformibius, Globicatella and Actinobacillus were more abundant in LPS-challenged gilts in indoor group housing than in SAL gilts in the same housing system. Gilts kept outdoors did not show changes in vaginal microbiota after an LPS challenge. Gilts housed in crates showed clinical signs of urogenital infection, whereas gilts housed outdoors and in indoor group housing did not. The relationship between environment, immune response, and microbiota suggested that animals in a poor environments experience difficulties responding to a challenge and their vaginal microbiota is altered as a consequence, with decreased richness of normal vaginal microbiota, and increased opportunistic bacteria. Welfare indicators measured by gilts’ responses to housing systems however, do not fully explain mechanisms associated with the unique signature in vaginal microbiota encountered in the different housing systems.

For a structured response to the psychosocial consequences of the restrictive measures imposed by the global COVID-19 health pandemic: the MAVIPAN longitudinal prospective cohort study protocol

INTRODUCTION

The COVID-19 pandemic and associated restrictive measures have caused important disruptions in economies and labour markets, changed the way we work and socialise, forced schools to close and healthcare and social services to reorganise. This unprecedented crisis forces individuals to make considerable efforts to adapt and will have psychological and social consequences, mainly on vulnerable individuals, that will remain once the pandemic is contained and will most likely exacerbate existing social and gender health inequalities. This crisis also puts a toll on the capacity of our healthcare and social services structures to provide timely and adequate care. The MAVIPAN (Ma vie et la pandémie/ My Life and the Pandemic) study aims to document how individuals, families, healthcare workers and health organisations are affected by the pandemic and how they adapt.

METHODS AND ANALYSIS

MAVIPAN is a 5-year longitudinal prospective cohort study launched in April 2020 across the province of Quebec (Canada). Quantitative data will be collected through online questionnaires (4-6 times/year) according to the evolution of the pandemic. Qualitative data will be collected with individual and group interviews and will seek to deepen our understanding of coping strategies. Analysis will be conducted under a mixed-method umbrella, with both sequential and simultaneous analyses of quantitative and qualitative data.

ETHICS AND DISSEMINATION

MAVIPAN aims to support the healthcare and social services system response by providing high-quality, real-time information needed to identify those who are most affected by the pandemic and by guiding public health authorities' decision making regarding intervention and resource allocation to mitigate these impacts. MAVIPAN was approved by the Ethics Committees of the Primary Care and Population Health Research Sector of CIUSSS de la Capitale-Nationale (Committee of record) and of the additional participating institutions.

TRIAL REGISTRATION NUMBER

NCT04575571.

Early pregnancy anxiety during the COVID-19 pandemic: preliminary findings from the UCSF ASPIRE study

BACKGROUND

Antenatal anxiety has been linked to adverse obstetric outcomes, including miscarriage and preterm birth. However, most studies investigating anxiety during pregnancy, particularly during the COVID-19 pandemic, have focused on symptoms during the second and third trimester. This study aims to describe the prevalence of anxiety symptoms early in pregnancy and identify predictors of early pregnancy anxiety during the COVID-19 pandemic.

METHODS

We assessed baseline moderate-to-severe anxiety symptoms after enrollment in the UCSF ASPIRE (Assessing the Safety of Pregnancy in the Coronavirus Pandemic) Prospective Cohort from May 2020 through February 2021. Pregnant persons < 10 weeks' gestation completed questions regarding sociodemographic characteristics, obstetric/medical history, and pandemic-related experiences. Univariate and multivariate hierarchical logistic regression analyses determined predictors of moderate or severe anxiety symptoms (Generalized Anxiety Disorder-7 questionnaire score ≥ 10). All analyses performed with Statistical Analysis Software (SAS®) version 9.4.

RESULTS

A total of 4,303 persons completed the questionnaire. The mean age of this nationwide sample was 33 years of age and 25.7% of participants received care through a fertility clinic. Over twelve percent of pregnant persons reported moderate-to-severe anxiety symptoms. In univariate analysis, less than a college education (p < 0.0001), a pre-existing history of anxiety (p < 0.0001), and a history of prior miscarriage (p = 0.0143) were strong predictors of moderate-to-severe anxiety symptoms. Conversely, having received care at a fertility center was protective (26.6% vs. 25.7%, p = 0.0009). COVID-19 related stressors including job loss, reduced work hours during the pandemic, inability to pay rent, very or extreme worry about COVID-19, and perceived stress were strongly predictive of anxiety in pregnancy (p < 0.0001). In the hierarchical logistic regression model, pre-existing history of anxiety remained associated with anxiety during pregnancy, while the significance of the effect of education was attenuated.

CONCLUSION(S)

Pre-existing history of anxiety and socioeconomic factors likely exacerbated the impact of pandemic-related stressors on early pregnancy anxiety symptoms during the COVID-19 pandemic. Despite on-going limitations for in-person prenatal care administration, continued emotional health support should remain an important focus for providers, particularly when caring for less privileged pregnant persons or those with a pre-existing history of anxiety.

Early environmental enrichment prevents cognitive impairments and developing addictive behaviours in a mouse model of prenatal psychological and physical stress

Environmental enrichment (EE) has shown remarkable effects in improving cognition and addictive behaviour. We tested whether EE could help recover from prenatal stress exposure. Mature Swiss Webster male and virgin female mice were placed together until vaginal plugs were detectable. Next, pregnant rodents were randomized into the control, physically and psychologically stressed groups. The application of stress was initiated on the 10th day of pregnancy and persisted for a week to induce stress in the mice. Open field and elevated plus-maze (EPM) tests were utilized as explorative and anxiety assays, respectively. A passive avoidance shuttle-box test was carried out to check anxiety-modulated behaviour. Morris water maze (MWM) test was undertaken to evaluate spatial learning and memory. Conditioned place preference (CPP) test was selected for evaluation of tendency to morphine consumption. Our results showed that prenatal stress elevated anxiety-like behaviour in the offspring which EE could significantly alleviate after weaning. We also found a higher preference for morphine use in the physical stress and psychological stress offspring group. However, no difference was observed among the genders. Application of EE for the stress group improved several parameters of the cognitive behaviour significantly. Although prenatal stress can lead to detrimental behavioural and cognitive outcomes, it can in part be relieved by early exposure to EE. However, some outcomes linked to prenatal stress exposure may not be diminished by EE therapy. In light of such irreversible effects, large-scale preventive actions promoting avoidance from stress during pregnancy should be advised.

Stress System Activation in Children and Adolescents With Autism Spectrum Disorder

The mission of the human stress system is the maintenance of homeostasis in the presence of real or perceived, acute or chronic stressors. The hypothalamic–pituitary–adrenal (HPA) axis and the autonomic nervous system (ANS) are the stress system-related neuroendocrine pathways. There is abundant evidence that children and adolescents with autism spectrum disorder (ASD) may exhibit atypical function within the HPA axis and the ANS both at the resting state and during the presence of social and/or non-social stressors. The aim of this review is to provide an up-to-date summary of the findings regarding stress system alterations in children and adolescents with ASD. We focus on the variations of stress hormones circadian rhythms, specifically cortisol and alpha-amylase (i.e., a surrogate index of epinephrine/norepinephrine secretion), and on the alterations of stress system responsivity to different stressors. Also, we present imaging and immunological findings that have been associated with stress system dysregulation in children and adolescents with ASD. Finally, we review the pivotal role of HPA axis-ANS coordination, the developmental trajectory of the stress system in ASD, and the possible role of early life stress in the dysregulation of the stress system demonstrated in children and adolescents with ASD. This synthesis will hopefully provide researchers with a foundation for an integrated approach to future research into stress system variations in children and adolescents with ASD.

Sex-specific associations between maternal pregnancy-specific anxiety and newborn amygdalar volumes - preliminary findings from the FinnBrain Birth Cohort Study

Previous literature links maternal pregnancy-specific anxiety (PSA) with later difficulties in child emotional and social cognition as well as memory, functions closely related to the amygdala and the hippocampus. Some evidence also suggests that PSA affects child amygdalar volumes in a sex-dependent way. However, no studies investigating the associations between PSA and newborn amygdalar and hippocampal volumes have been reported. We investigated the associations between PSA and newborn amygdalar and hippocampal volumes and whether associations are sex-specific in 122 healthy newborns (68 males/54 females) scanned at 2-5 weeks postpartum. PSA was measured at gestational week 24 with the Pregnancy-Related Anxiety Questionnaire Revised 2 (PRAQ-R2). The associations were analyzed with linear regression controlling for confounding variables. PSA was associated positively with left amygdalar volume in girls, but no significant main effect was found in the whole group or in boys. No significant main or sex-specific effect was found for hippocampal volumes. Although this was an exploratory study, the findings suggest a sexually dimorphic association of mid-pregnancy PSA with newborn amygdalar volumes.

Heat stress affects fetal brain and intestinal function associated with the alterations of placental barrier in late pregnant mouse

High ambient temperature-induced heat stress (HS) during pregnancy may affect the placental function and fetal development. Late gestation is a critical period of the developing fetal brain and intestine. The study aimed to investigate the effects of HS during late pregnancy on the function of placenta, fetal brain and intestine in a mouse model. We found that the number of stillborn fetal mice were increased due to maternal HS. Transcriptome analysis revealed that the expression of genes enriched in nutrients transport and metabolism of HS group were up-regulated in the placenta, but down-regulated in the fetal duodenum and jejunum. Interestingly, the concentration of triglyceride (TG) in the HS group was raised in the placenta, but reduced both in the fetal duodenum and jejunum compared with the thermal-neutral (TN) group. Additionally, maternal HS also reduced total cholesterol (TC) contents in the fetal duodenum. The mRNA expression and protein levels of placental fatty acid binding protein 2 and 4 (fabp2 and fabp4) were not affected by maternal HS, but the mRNA expression and protein levels of cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase-2 (Dgat2) were decreased in the fetal intestine. Furthermore, maternal HS reduced the mRNA expression and protein levels of the placental 11beta-hydroxysteroid dehydrogenase type 2 (Hsd11b2) and 5-hydroxytryptamine receptor 1D (Htr1d). The concentrations of corticosterone and the expression of heat shock protein 90 beta family member 1 (hsp90b1), hypoxia up-regulated 1 (hyou1) and corticotropin releasing hormone receptor 1 (crhr1) enriched in response to glucocorticoids in the fetal brain were increased by maternal HS. Taken together, our findings demonstrated that maternal HS disrupted the placental glucocorticoid barrier and serotonin system associated with the raised corticosterone levels in the fetal brain, which might contribute to the decreased capacity of nutrients transport and metabolism in the fetal intestine.

Acute hypoxia exposure following prenatal stress impairs hippocampus and novelty-seeking behavior in adolescent rats

OBJECTIVES

The present study aimed to investigate the effects of acute hypoxia exposure following prenatal stress on the novelty-seeking behavior and hippocampus of adolescent rats.

METHODS

The offspring were divided into prenatal stress (PS) and non-stress (NS) groups. Both groups were exposed to hypoxia on postnatal day 10 (P10) while control groups were undisturbed. Novel object recognition task was performed in each group. Next, brains were collected to examine hippocampus via immunohistochemical and biochemical studies on postnatal day 35 (P35).

RESULTS

PS decreased novelty discrimination and synaptophysin (SYN) expressions in both CA1 and CA3 of the hypoxia group prominently (p < 0.05). Nestin-expressing cells were reduced while vascular endothelial growth factor (VEGF) expression was enhanced in the subgranular zone (SGZ) of PS-hypoxia group (p < 0.05). VEGF enhancement triggered angiogenesis in the CA1 and CA3 significantly (p < 0.05). PS also increased thiobarbituric acid reactive substances (TBARS) levels in the hypoxia group as a result of oxidative stress (p < 0.05).

CONCLUSION

These findings demonstrated that PS exacerbates neurodevelopmental deficits in the hippocampus of acute hypoxia-induced offspring in adolescence.