Evidence for developmental programming of cerebral laterality in humans

Stability of associations between neuroticism and microstructural asymmetry of the cingulum during late childhood and adolescence: Insights from a longitudinal study with up to 11 waves

Adolescence is characterized by significant brain development and marks a period of the life span with an increased incidence of mood disorders, especially in females. The risk of developing mood disorders is also higher in individuals scoring high on neuroticism, a personality trait characterized by a tendency to experience negative and anxious emotions. We previously found in a cross-sectional study that neuroticism is associated with microstructural left-right asymmetry of the fronto-limbic white matter involved in emotional processing, with opposite effects in female and male adolescents. We now have extended this work collecting longitudinal data in 76 typically developing children and adolescents aged 7-18 years, including repeated MRI sampling up to 11 times. This enabled us, for the first time, to address the critical question, whether the association between neuroticism and frontal-limbic white matter asymmetry changes or remains stable across late childhood and adolescence. Neuroticism was assessed up to four times and showed good intraindividual stability and did not significantly change with age. Conforming our cross-sectional results, females scoring high on neuroticism displayed increased left-right cingulum fractional anisotropy (FA), while males showed decreased left-right cingulum FA asymmetry. Despite ongoing age-related increases in FA in cingulum, the association between neuroticism and cingulum FA asymmetry was already expressed in females in late childhood and remained stable across adolescence. In males, the association appeared to become more prominent during adolescence. Future longitudinal studies need to cover an earlier age span to elucidate the time point at which the relationship between neuroticism and cingulum FA asymmetry arises.

Maternal prenatal infection and anxiety predict neurodevelopmental outcomes in middle childhood

Prenatal maternal infection and anxiety have been linked, in separate lines of study, with child neurodevelopment. We extend and integrate these lines of study in a large prospective longitudinal cohort study of child neurodevelopment. Data are based on the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort; prenatal maternal anxiety was assessed from self-report questionnaire; prenatal infection was derived from reports of several conditions in pregnancy (n = 7,042). Child neurodevelopment at approximately 8 years of age was assessed by in-person testing, reports of social and communication problems associated with autism, and psychiatric evaluation. Covariates included psychosocial, demographic, and perinatal/obstetric risks. Prenatal infection was associated with increased likelihood of co-occurring prenatal risk, including anxiety. Regression analyses indicated that both prenatal infection and prenatal anxiety predicted child social and communication problems; the predictions were largely independent of each other. Comparable effects were also found for the prediction of symptoms of attention problems and anxiety symptoms. These results provide the first evidence for the independent effects of prenatal infection and anxiety on a broad set of neurodevelopmental and behavioral and emotional symptoms in children, suggesting the involvement of multiple mechanisms in the prenatal programming of child neurodevelopment. The results further underscore the importance of promoting prenatal physical and mental health for child health outcomes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Modulation of Auditory Perception Laterality under Anxiety and Depression Conditions

The objective of this work is to confirm the asymmetry in non-linguistic auditory perception, as well as the influence of anxiety-depressive disorders on it. Eighty-six people were recruited in the emotional well-being group, fifty-six in the anxiety group, fourteen in the depression group, and seventy-seven in the mixed group. In each group, audiograms were obtained from both ears and the differences were statistically analyzed. Differences in hearing sensitivity were found between both ears in the general population, such differences increased in people with anxiety-depressive disorders. When faced with anxiety-depressive disorders, the right ear suffered greater hearing loss than the left, showing peaks of hyper-hearing at the frequency of 4000 Hz in the anxiety subgroup, and hearing loss in the depression subgroup. In relation to anxiety, the appearance of the 4:8 pattern was observed in the right ear when the person had suffered acute stress in the 2 days prior to the audiometry, and in both ears if they had suffered stress in the 3–30 days before said stress. In conclusion, the advantage of the left ear in auditory perception was increased with these disorders, showing a hyperaudition peak in anxiety and a hearing loss in depression.

Cohort profile: Understanding Pregnancy Signals and Infant Development (UPSIDE): a pregnancy cohort study on prenatal exposure mechanisms for child health

PURPOSE

Extensive research suggests that maternal prenatal distress is reliably related to perinatal and child health outcomes-which may persist into adulthood. However, basic questions remain regarding mechanisms involved. To better understand these mechanisms, we developed the Understanding Pregnancy Signals and Infant Development (UPSIDE) cohort study, which has several distinguishing features, including repeated assessments across trimesters, analysis of multiple biological pathways of interest, and incorporation of placental structure and function as mediators of child health outcomes.

PARTICIPANTS

Women with normal risk pregnancies were recruited at <14 weeks gestation. Study visits occurred in each trimester and included extensive psychological, sociodemographic, health behaviour and biospecimen collection. Placenta and cord blood were collected at birth. Child visits (ongoing) occur at birth and 1, 6, 12, 24, 36 and 48 months of age and use standard anthropometric, clinical, behavioural, biological and neuroimaging methods to assess child physical and neurodevelopment.

FINDINGS TO DATE

We recruited 326 pregnancies; 294 (90%) were retained through birth. Success rates for prenatal biospecimen collection were high across all trimesters (96%-99% for blood, 94%-97% for urine, 96%-99% for saliva, 96% of placentas, 88% for cord blood and 93% for buccal swab). Ninety-four per cent of eligible babies (n=277) participated in a birth examination; postnatal visits are ongoing.

FUTURE PLANS

The current phase of the study follows children through age 4 to examine child neurodevelopment and physical development. In addition, the cohort participates in the National Institutes of Health's Environmental influences on Child Health Outcomes programme, a national study of 50 000 families examining early environmental influences on perinatal outcomes, neurodevelopment, obesity and airway disease. Future research will leverage the rich repository of biological samples and clinical data to expand research on the mechanisms of child health outcomes in relation to environmental chemical exposures, genetics and the microbiome.

Atypical lateralization in neurodevelopmental and psychiatric disorders: What is the role of stress?

Hemispheric asymmetries are a major organizational principle of the human brain. In different neurodevelopmental and psychiatric disorders, like schizophrenia, autism spectrum disorders, depression, dyslexia and posttraumatic stress disorder, functional and/or structural hemispheric asymmetries are altered compared to healthy controls. The question, why these disorders all share the common characteristic of altered hemispheric asymmetries despite vastly different etiologies and symptoms remains one of the unsolved mysteries of laterality research. This review is aimed at reviewing potential reasons for why atypical lateralization is so common in many neurodevelopmental and psychiatric disorders. To this end, we review the evidence for overlaps in the genetic and non-genetic factors involved in the ontogenesis of different disorders and hemispheric asymmetries. While there is evidence for genetic overlap between different disorders, only few asymmetry-related loci have also been linked to disorders and importantly, those effects are mostly specific to single disorders. However, there is evidence for shared non-genetic influences between disorders and hemispheric asymmetries. Most neurodevelopmental and psychiatric disorders show alterations in the hypothalamic-pituitary adrenocortical (HPA) axis and maternal as well as early life stress have been implicated in their etiology. Stress has also been suggested to affect hemispheric asymmetries. We propose a model in which early life stress as well as chronic stress not only increases the risk for psychiatric and neurodevelopmental disorders but also changes structural and functional hemispheric asymmetries leading to the aberrant lateralization patterns seen in these disorders. Thus, pathology-related changes in hemispheric asymmetries are not a factor causing disorders, but rather a different phenotype that is affected by partly overlapping ontogenetic factors, primarily stress.

Placental mitochondrial DNA content is associated with childhood intelligence

BACKGROUND

Developmental processes in the placenta and the fetal brain are shaped by the similar biological signals. Evidence accumulates that adaptive responses of the placenta may influence central nervous system development. We hypothesize that placental mtDNA content at birth is associated with intelligence in childhood. In addition, we investigate if intra-pair differences in mtDNA content are associated with intra-pair differences in intelligence.

METHODS

Relative mtDNA content was measured using qPCR in placental tissue of 375 children of the East Flanders Prospective Twin Survey. Intelligence was assessed with the Wechsler Intelligence Scale for Children-Revised (WISC-R) between 8 and 15 years old. We accounted for sex, gestational age, birth weight, birth year, zygosity and chorionicity, cord insertion, age at measurement, indicators of socioeconomic status, smoking during pregnancy, and urban environment.

RESULTS

In multivariable adjusted mixed modelling analysis, each doubling in placental mtDNA content was associated with 2.0 points (95% CI 0.02 to 3.9; p = 0.05) higher total and 2.3 points (95% CI 0.2 to 4.3; p = 0.03) higher performance IQ in childhood. We observed no association between mtDNA content and verbal intelligence. Intra-pair differences in mtDNA content and IQ were significantly (p = 0.01) correlated in monozygotic-monochorionic twin pairs, showing that the twin with the highest mtDNA content was 1.9 times more likely (p = 0.05) to have the highest IQ. This was not observed in dichorionic twin pairs.

CONCLUSIONS

We provide the first evidence that placental mtDNA content is associated with childhood intelligence. This emphasizes the importance of placental mitochondrial function during in utero life on fetal brain development with long-lasting consequences.

Difference in Z scores of placental weight and fetal/placental weight ratio by mode of delivery

AIM

The difference of placental weight (PW) and fetal/placental weight ratio (F/P) Z scores by mode of delivery is unclear. To investigate such differences and the actual conditions underlying the imbalance between fetal and placental growth.

METHODS

The data from Japanese database 2013 were assessed. Light-for-dates (LFD, n = 12 884), appropriate-for-dates (n = 114 464) and heavy-for-dates (n = 13 164) from 140 512 placentas/infants of mothers delivered a singleton infant. Using Z scores of PW and F/P based on the standard curves of a sex-, parity- and gestational-age-specific PW and F/P, the rate of inappropriately heavy placenta according to the mode of delivery (vaginal [VD] vs cesarean [CS]) was investigated.

RESULTS

(i) The PW and F/P were heavier and bigger in VD than in CS, in each subgroup. In the LFD groups, the PW Z score in VD was higher than that in CS, whereas the F/P Z score was lower than in VD than that in CS. (ii) Data of single regression analyses between the PW Z score and F/P Z score in VD groups were different from those in CS, especially in LFD infants. (iii) In the LFD subgroups, the rates of inappropriately heavy placenta in VD (n = 7781) and CS (n = 5103) were 0.54% and 0.86%, respectively.

CONCLUSION

Difference in the mode of delivery influenced the PW and F/P, and the rate of inappropriately heavy placenta is associated with mode of delivery among LFD infants. This methodology might give us a clue to search a useful way for identifying the high-risk groups requiring postnatal counseling.

Effects of induced placental and fetal growth restriction, size at birth and early neonatal growth on behavioural and brain structural lateralization in sheep

Poor perinatal growth in humans results in asymmetrical grey matter loss in fetuses and infants and increased functional and behavioural asymmetry, but specific contributions of pre- and postnatal growth are unclear. We therefore compared strength and direction of lateralization in obstacle avoidance and maze exit preference tasks in offspring of placentally restricted (PR: 10M, 13F) and control (CON: 23M, 17F) sheep pregnancies at 18 and 40 weeks of age, and examined gross brain structure of the prefrontal cortex at 52 weeks of age (PR: 14M, 18F; CON: 23M, 25F). PR did not affect lateralization direction, but 40-week-old PR females had greater lateralization strength than CON (P = .021). Behavioural lateralization measures were not correlated with perinatal growth. PR did not alter brain morphology. In males, cross-sectional areas of the prefrontal cortex and left hemisphere correlated positively with skull width at birth, and white matter area correlated positively with neonatal growth rate of the skull (all P < .05). These studies reinforce the need to include progeny of both sexes in future studies of neurodevelopmental programming, and suggest that restricting in utero growth has relatively mild effects on gross brain structural or behavioural lateralization in sheep.

Selected Gray Matter Volumes and Gender but Not Basal Ganglia nor Cerebellum Gyri Discriminate Left Versus Right Cerebral Hemispheres: Multivariate Analyses in human Brains at 3T

Interest in the lateralization of the human brain is evident through a multidisciplinary number of scientific studies. Understanding volumetric brain asymmetries allows the distinction between normal development stages and behavior, as well as brain diseases. We aimed to evaluate volumetric asymmetries in order to select the best gyri able to classify right- versus left cerebral hemispheres. A cross-sectional study performed in 47 right-handed young-adults healthy volunteers. SPM-based software performed brain segmentation, automatic labeling and volumetric analyses for 54 regions involving the cerebral lobes, basal ganglia and cerebellum from each cerebral hemisphere. Multivariate discriminant analysis (DA) allowed the assembling of a predictive model. DA revealed one discriminant function that significantly differentiated left vs. right cerebral hemispheres: Wilks' λ = 0.008, χ(2) (9) = 238.837, P < 0.001. The model explained 99.20% of the variation in the grouping variable and depicted an overall predictive accuracy of 98.8%. With the influence of gender; the selected gyri able to discriminate between hemispheres were middle orbital frontal gyrus (g.), angular g., supramarginal g., middle cingulum g., inferior orbital frontal g., calcarine g., inferior parietal lobule and the pars triangularis inferior frontal g. Specific brain gyri are able to accurately classify left vs. right cerebral hemispheres by using a multivariate approach; the selected regions correspond to key brain areas involved in attention, internal thought, vision and language; our findings favored the concept that lateralization has been evolutionary favored by mental processes increasing cognitive efficiency and brain capacity.

Tympanic membrane temperature in adopted children associated with sleep problems and pre-adoption living arrangements: an exploratory study

Background

Tympanic membrane temperature (TMT) has been proposed as an indicator of cerebral activation and TMT asymmetry may indicate lateralization, which has been associated with specific (problem) behaviors in children and adults. The current study explored the relations between pre-adoption living arrangements, TMT, and behavior and sleep problems in a sample of adopted toddlers.

Methods

Ninety-two families who had adopted a Chinese girl who had previously been placed in an institution or foster care reported on behavior problems using the Child Behavior Checklist and TMT two months (Time 1) and six months (Time 2) after adoption.

Results

Structural equation modeling revealed that institutionalized children had significantly higher left than right TMTs compared with foster care children at Time 2. A higher left than right TMT was associated with increased sleep problems and total behavior problems at Time 1, but not at Time 2.

Conclusions

Our findings with regard to pre-adoption living arrangements, TMT asymmetry, and sleep problems suggest that TMT is sensitive to early environmental influences and may be a biological marker of vulnerability to the development of sleep problems in children from adverse backgrounds.

Functional connectivity in prenatally stressed rats with and without maternal treatment with ladostigil, a brain-selective monoamine oxidase inhibitor

Stress during pregnancy in humans is known to be a risk factor for neuropsychiatric disorders in the offspring. Prenatal stress in rats caused depressive-like behavior that was restored to that of controls by maternal treatment with ladostigil (8.5 mg/kg per day), a brain-selective monoamine oxidase (MAO) inhibitor that prevented increased anxiety-like behavior in stressed mothers. Ladostigil inhibited maternal striatal MAO-A and -B by 45-50% at the time the pups were weaned. Using resting state-functional connectivity magnetic resonance imaging on rat male offspring of control mothers, and mothers stressed during gestation with and without ladostigil treatment, we identified neuronal connections that differed between these groups. The percentage of significant connections within a predefined predominantly limbic network in control rats was 23.3 within the right and 22.0 within the left hemisphere. Prenatal stress disturbed hemispheric symmetry, resulting in 30.2 and 21.6%, significant connections in the right and left hemispheres, respectively, but this was fully restored in the maternal ladostigil group to 24.6% in both hemispheres. All connections that were modified in prenatally stressed rats and restored by maternal drug treatment were associated with the dopaminergic system. Specifically, we observed that restoration of the connections of the right nucleus accumbens shell with frontal areas, the cingulate, septum and motor and sensory cortices, and those of the right globus pallidus with the infra-limbic and the dentate gyrus, were most important for prevention of depressive-like behavior.

Limbic system activation is affected by prenatal predator exposure and postnatal environmental enrichment and further moderated by dam and sex

Epilepsy is a relatively common and chronic neurological condition, affecting 1-2% of the population. However, understanding of the underlying pathophysiology remains incomplete. To identify potential factors in the early environment that may increase the risk for experiencing seizures, maternal stress and environmental enrichment (EE) were utilized. Pregnant Long-Evans rats were exposed to an ethologically relevant predator stress (PS) and maternal glucocorticoid (GC) response was assessed across the exposure period. At birth, litters were divided into standard care (SC) and EE groups until postnatal day 14 (PD14) when a model of febrile convulsions was used to determine seizure susceptibility of the various groups. Pup brains were then processed for immunohistochemical detection of FosB from several structures in the limbic system as a measure of neuronal activation. Maternal PS-induced GC levels were elevated early in the exposure period, and pup birth weights, in both sexes, were lower in litters from dams exposed to PS. Seizure scores at PD14 were highly individualized and litter dependent, suggesting a dam-dependent and variable effect of controlled pre- and postnatal environmental factors. Further, analysis of FosB-immunoreactive (-ir) patterns revealed an activity dependent distribution, reflecting individual seizure susceptibility. EE had a varying effect on FosB-ir that was dependent on region. In the hippocampus FosB-ir levels were greater in the EE groups while extra-hippocampal regions showed lower levels of FosB-ir. Our results support the concept that pre- and postnatal environmental influences affect fetal programming and neurodevelopment of processes that could underlie seizure susceptibility, but that the magnitude of these effects appears to be dam- or litter-dependent.

Cortisol awakening response in infants during the first six postnatal months and its relation to birth outcome

CONTEXT

The rise of cortisol concentrations after awakening is well documented in adults and children and commonly used as easily accessible marker of hypothalamic-pituitary-adrenal (HPA) reactivity.

OBJECTIVE

The purpose of this study was to demonstrate the existence of a salivary cortisol awakening response (CAR) in infants, and to estimate its association with birth outcome.

SETTING

The study was conducted in the general community.

PARTICIPANTS

Healthy infants up to six months age (N=64).

MAIN OUTCOME MEASURES

Mothers were instructed to collect their infant's saliva immediately and 30 min after awakening on two days within 45 days, irrespective of awakening time. Information on birth outcome was collected from medical records and questionnaires.

RESULTS

Linear mixed models analysis revealed a significant rise of infant salivary cortisol concentrations within 30 min after awakening (b=0.128, SE=0.024, t61=5.31, p<0.001), which was quite stable across the two sampling days (r=0.40, p=0.002). The infant CAR was predicted by length of gestation (t58=2.44, p=0.018).

CONCLUSIONS

The current data demonstrate the existence of a CAR in infants as early as during the first six postnatal months; its relationship with length of gestation supports its usefulness for questions related to developmental neuroscience. Therefore, the infant CAR emerges as non-invasive biomarker of HPA axis dynamics at this early stage of life, with relevance for future research and potential clinical applications.

Comparing biobehavioral profiles across two social stress paradigms in children with and without autism spectrum disorders

BACKGROUND

Autism spectrum disorders (ASD) are defined by impairment in reciprocal social interaction and flexible adaptation to the environment. This study compared physiological stress in children with and without ASD exposed to two social stress protocols. We hypothesized that the ASD group would show heightened initial and enduring cortisol levels to the social stressors, which would be moderated by age and intelligence.

METHODS

Twenty-seven children with ASD and 32 with typical development (TYP) completed a standardized social-evaluative performance task and a validated paradigm of social play with peers. Physiological stress was measured by salivary cortisol at nine time points. Statistical approaches included repeated-measures linear mixed models and correlation analyses.

RESULTS

The average cortisol level of both groups during initial exposure to social situations was significantly greater than baseline levels (ASD, P = 0.018; TYP, P = 0.006). Stress responsivity was significantly different between the groups; the TYP group showed a significant reduction in cortisol over time (P = 0.023), whereas the ASD group maintained an elevated cortisol level (P >0.05). The ASD group evidenced greater variability in between-group, within-group and intra-individual analyses. Age was a positive moderator of stress for the ASD group (P = 0.047), whereas IQ was a negative moderator for the TYP group (P = 0.061).

CONCLUSIONS

Initial stress to novel social scenarios is idiosyncratic and predictive of subsequent exposure. Amidst significant variability in cortisol, children with ASD show enhanced and sustained social stress that increases with age. Developmental and cognitive factors differentially moderate stress in children with ASD and TYP, respectively. A model of neuroendocrine reactivity is proposed.

Placental size is associated with mental health in children and adolescents

BACKGROUND

The role of the placenta in fetal programming has been recognized as a highly significant, yet often neglected area of study. We investigated placental size in relation to psychopathology, in particular attention deficit hyperactivity disorder (ADHD) symptoms, in children at 8 years of age, and later as adolescents at 16 years.

METHODOLOGY/PRINCIPAL FINDINGS

Prospective data were obtained from The Northern Finland Birth Cohort (NFBC) 1986. Placental weight, surface area and birth weight were measured according to standard procedures, within 30 minutes after birth. ADHD symptoms, probable psychiatric disturbance, antisocial disorder and neurotic disorder were assessed at 8 years (n = 8101), and ADHD symptoms were assessed again at 16 years (n = 6607), by teachers and parents respectively. We used logistic regression analyses to investigate the association between placental size and mental health outcomes, and controlled for gestational age, birth weight, socio-demographic factors and medical factors, during gestation. There were significant positive associations between placental size (weight, surface area and placental-to-birth-weight ratio) and mental health problems in boys at 8 and 16 years of age. Increased placental weight was linked with overall probable psychiatric disturbance (at 8 y, OR= 1.14 [95% CI= 1.04-1.25]), antisocial behavior (at 8 y, OR = 1.14 [95% CI= 1.03-1.27]) and ADHD symptoms (inattention-hyperactivity at 16 y, OR= 1.19 [95% CI = 1.02-1.38]). No significant associations were detected among girls.

CONCLUSIONS/SIGNIFICANCE

Compensatory placental growth may occur in response to prenatal insults. Such overgrowth may affect fetal development, including brain development, and ultimately contribute to psychopathology.

Perinatal effects on in vivo measures of human brain serotonin synthesis in adulthood: a 27-year longitudinal study

There is an increasing evidence that prenatal and early postnatal stressors have life long impacts on physical and mental health problems. Animal studies have shown that this could include enduring changes to brain serotonin neurotransmission. In the present study, we tested whether perinatal adversity in humans has a long-term impact on brain serotonin neurotransmission in adulthood. Twenty-six healthy males, recruited from a 27-year longitudinal study, underwent a positron emission tomography scan with the tracer alpha-[¹¹C]methyl-L-tryptophan (¹¹C-AMT), as an index of serotonin synthesis capacity. The trapping constant is taken as a proxy for the regional 5-HT synthesis. Birth complications, especially a delivery where the fetus showed signs of physiological distress, predicted lower ¹¹C-AMT trapping in the hippocampus and medial orbitofrontal cortex. Lower ¹¹C-AMT trapping in the medial orbitofrontal cortex was also predicted by maternal smoking and lower birth weight. There were no effects of childhood or recent adversity. This is the first human study reporting associations between perinatal adversity and adult ¹¹C-AMT trapping in the hippocampus and medial orbitofrontal cortex. The associations suggest that limbic serotonin pathways may be particularly vulnerable to environmental challenges during the period when they undergo the most prominent neurodevelopmental changes. In combination with other risk factors, perinatal stressors may contribute to increased vulnerability for psychiatric disorders in which serotonin plays a major role.

Classification of clinical semiology in epileptic seizures in neonates

The clinical semiology of 61 neonatal seizures with EEG correlates, in 24 babies was analysed. Most seizures (89%) had multiple features during the EEG discharge. The seizures were classified using the prominent clinical feature at onset, and all features seen during the seizure, using an extended classification scheme. Orolingual features occurred most frequently at onset (30%), whereas ocular phenomena occurred most often during the seizure (70%). Orolingual, ocular and autonomic features were seen at onset in 55% of the seizures. Seizure onsets with clonic, tonic and hypomotor features were seen in 20%, 8% and 18% respectively. Clinico-electrical correlations were as follows. The EEG discharge involved both hemispheres in 54% of all seizures, in clonic seizures this was 93%. Focal clonic seizures were associated with EEG seizure onset from the contralateral hemisphere. Majority of the clonic and hypomotor seizures had a left hemisphere ictal EEG onset. Orolingual seizures frequently started from the right hemisphere, whereas ocular and autonomic seizures arose from either hemisphere. There was no significant difference in mortality, morbidity, abnormal neuroimaging and EEG background abnormalities in babies with or without clonic seizures. This study provides insights into neuronal networks that underpin electroclinical seizures, by analysing and classifying the obvious initial clinical features and those during the seizure.