Decreased amygdala-sensorimotor connectivity mediates the association between prenatal stress and broad autism phenotype in young adults: Project Ice Storm.

Studies show that prenatal maternal stress (PNMS) is related to risk for child autism, and to atypical amygdala functional connectivity in the autistic child. Yet, it remains unclear whether amygdala functional connectivity mediates the association between PNMS and autistic traits, particularly in young adult offspring. We recruited women who were pregnant during, or within 3 months of, the 1998 Quebec ice storm crisis, and assessed three aspects of PNMS: objective hardship (events experienced during the ice storm), subjective distress (post-traumatic stress symptoms experienced as a result of the ice storm) and cognitive appraisal. At age 19, 32 young adults (21 females) self-reported their autistic-like traits (i.e., aloof personality, pragmatic language impairment and rigid personality), and underwent structural MRI and resting-state functional MRI scans. Seed-to-voxel analyses were conducted to map the amygdala functional connectivity network. Mediation analyses were implemented with bootstrapping of 20,000 resamplings. We found that greater maternal objective hardship was associated with weaker functional connectivity between the left amygdala and the right postcentral gyrus, which was then associated with more pragmatic language impairment. Greater maternal subjective distress was associated with weaker functional connectivity between the right amygdala and the left precentral gyrus, which was then associated with more aloof personality. Our results demonstrate that the long-lasting effect of PNMS on offspring autistic-like traits may be mediated by decreased amygdala-sensorimotor circuits. The differences between amygdala-sensory and amygdala-motor pathways mediating different aspects of PNMS on different autism phenotypes need to be studied further.

Enriched Rehabilitation Reduces Abnormal Motor Synergies and Enhances Motor Plasticity Following Severe Stroke in Rats.

BACKGROUND: Stroke results in loss of upper motor neuron control over voluntary movements and emergence of abnormal synergies. Presently, it is unclear to what extent poststroke recovery reflects true recovery (restitution), compensation, or some combination of these processes. Here, we investigated this question using behavioral and kinematic analyses of skilled reaching in rats subjected to severe stroke that affected both the forelimb motor cortex and dorsolateral striatum. METHODS: After stroke, male rats either spontaneously recovered or received enriched rehabilitation. We assessed forelimb motor recovery using behavioral and kinematic outcome measures. To provide insights into the mechanisms underlying the effects of rehabilitation on behavior, we used intracortical microstimulation and FosB (protein fosB) immunostaining techniques. RESULTS: Enriched rehabilitation significantly improved food pellet retrieval in the staircase-reaching task. Rehabilitation resulted in several poststroke flexion synergies returning to prestroke patterns, and across subjects, these changes correlated with the intensity of rehabilitation. Enriched rehabilitation increased the proportion of distal movement representation in the perilesional cortex and increased use-dependent activation in the ipsilesional red nucleus. CONCLUSIONS: These results provide evidence that enriched rehabilitation enhances recovery, at least in part, by restitution of forelimb function following severe stroke. Furthermore, the restitution of function is associated with changes in multiple motor-related structures at different levels of the central nervous system. A better understanding of the processes that underlie improved motor performance, along with the identification of midbrain circuits activated by rehabilitation, represent new insights and potential targets for optimizing poststroke recovery.

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.

Maternal mental health mediates the effect of prenatal stress on infant temperament: The Harvey Mom Study.

Prenatal maternal stress and mental health problems are known to increase risk for developmental psychopathology in offspring, yet pathways leading to risk or resiliency are poorly understood. In a quasi-experimental design, we prospectively examined associations between disaster-related prenatal stress, maternal mental health symptoms, and infant temperament outcomes. Mothers who were pregnant during Hurricane Harvey (N = 527) reported on objective hardships (e.g., loss of belongings or income, evacuation, home flooding) related to the storm and subsequent mental health symptoms (anxiety/depression, posttraumatic stress) across time. At a postpartum assessment, mothers reported on their infant's temperament (negative affect, positive affect, orienting/regulatory capacity). Greater objective hardship indirectly predicted higher levels of infant orienting/regulatory capacity through its association with increased maternal posttraumatic stress symptoms. Greater objective hardship also indirectly predicted higher levels of infant negative affect through its association with increased maternal anxiety/depression symptoms across time. Our findings suggest a psychological mechanism linking prenatal stress with specific temperamental characteristics via maternal mental health symptoms. Findings point to the importance of high-quality assessment and mental health services for vulnerable women and young children.

Prenatal maternal stress was not associated with birthweight or gestational age at birth during COVID-19 restrictions in Australia: The BITTOC longitudinal cohort study.

BACKGROUND: Various forms of prenatal maternal stress (PNMS) have been reported to increase risk for preterm birth and low birthweight. However, the associations between specific components of stress - namely objective hardship and subjective distress - and birth outcomes are not well understood. AIMS: Here, we aimed to determine the relationship between birthweight and gestational age at birth and specific prenatal factors (infant gender and COVID-19 pandemic-related objective hardship, subjective distress, change in diet), and to determine whether effects of hardship are moderated by maternal subjective distress, change in diet, or infant gender. MATERIALS AND METHODS: As part of the Birth in the Time of COVID (BITTOC study), women (N = 2285) who delivered in Australia during the pandemic were recruited online between August 2020 and February 2021. We assessed objective hardship and subjective distress related to the COVID pandemic and restrictions, and birth outcomes through questionnaires that were completed at recruitment and two months post-partum. Analyses included hierarchical multiple regressions. RESULTS: No associations between maternal objective hardship or subjective distress and gestational age at birth or birthweight were identified. Lower birthweight was significantly associated with female gender (adjusted ß = 0.083, P < 0.001) and with self-reported improvement in maternal diet (adjusted ß = 0.059, P = 0.015). CONCLUSIONS: In a socioeconomically advantaged sample, neither objective hardship nor subjective distress related to COVID-19 were associated with birth outcomes. Further research is warranted to understand how other individual factors influence susceptibility to PNMS and how these findings are applicable to women with lower socioeconomic status.

The mental health impacts of receiving a breast cancer diagnosis: A meta-analysis.

BACKGROUND: Receiving a breast cancer diagnosis can be a turning point with negative impacts on mental health, treatment and prognosis. This meta-analysis sought to determine the nature and prevalence of clinically significant psychological distress-related symptoms in the wake of a breast cancer diagnosis. METHODS: Ten databases were searched between March and August 2020. Thirty-nine quantitative studies were meta-analysed. RESULTS: The prevalence of clinically significant symptoms was 39% for non-specific distress (n = 13), 34% for anxiety (n = 19), 31% for post-traumatic stress (n = 7) and 20% for depression (n = 25). No studies reporting breast cancer patients' well-being in our specific time frame were found. CONCLUSION: Mental health can be impacted in at least four domains following a diagnosis of breast cancer and such effects are commonplace. This study outlines a clear need for mitigating the impacts on mental health brought about by breast cancer diagnosis. CRD42020203990.

Unexpected effects of expressive writing on post-disaster distress in the Hurricane Harvey Study: a randomized controlled trial in perinatal women.

BACKGROUND: Expressive writing requires journaling stressor-related thoughts and feelings over four daily sessions of 15 min. Thirty years of research have popularized expressive writing as a brief intervention for fostering trauma-related resilience; however, its ability to surpass placebo remains unclear. This study aimed to determine the efficacy of expressive writing for improving post-traumatic stress symptoms in perinatal women who were living in the Houston area during major flooding caused by Hurricane Harvey. METHODS: A total of 1090 women were randomly allocated (1:1:1) to expressive writing, neutral writing or no writing. Interventions were internet-based. Online questionnaires were completed before randomization and at 2 months post-intervention. The primary outcome was post-traumatic stress symptoms, measured with the Impact of Event Scale-Revised; secondary outcomes were affective symptoms, measured with the 40-item Inventory of Depression and Anxiety Scales. Feelings throughout the intervention were reported daily using tailored questionnaires. RESULTS: In intention-to-treat analyses, no post-treatment between-group differences were found on the primary and secondary outcomes. Per-protocol analyses yielded similar results. A number of putative moderators were tested, but none interacted with expressive writing. Expressive writing produced greater feelings of anxiety and sadness during the intervention compared to neutral writing; further, overall experiences from the intervention mediated associations between expressive writing and greater post-traumatic stress at 2 months post-intervention. CONCLUSIONS: Among disaster-stricken perinatal women, expressive writing was ineffective in reducing levels of post-traumatic stress, and may have exacerbated these symptoms in some.

Maternal Mental Health after a Wildfire: Effects of Social Support in the Fort McMurray Wood Buffalo Study.

OBJECTIVE: Following disasters, perinatal women are vulnerable to developing post-traumatic stress disorder (PTSD)-like symptoms. Little is known about protective factors. We hypothesized that peritraumatic stress would predict PTSD-like symptoms in pregnant and postpartum women and would be moderated by social support and resilience. METHOD: Women (n = 200) who experienced the 2016 Fort McMurray Wood Buffalo wildfire during or shortly before pregnancy completed the Peritraumatic Distress Inventory (PDI), Peritraumatic Dissociative Experiences Questionnaire, and the Impact of Event Scale-Revised for current PTSD-like symptoms. They also completed scales of social support (Social Support Questionnaire-Short Form) and resilience (Connor-Davidson Resilience Scale). RESULTS: Greater peritraumatic distress (r = 0.56) and dissociative experiences (r = 0.56) correlated with more severe PTSD-like symptoms. Greater social support satisfaction was associated with less severe post-traumatic stress symptoms but only when peritraumatic distress was below average; at more severe levels of PDI, this psychosocial variable was not protective. CONCLUSIONS: Maternal PTSD-like symptoms after a wildfire depend on peritraumatic distress and dissociation. Higher social support satisfaction buffers the association with peritraumatic distress, although not when peritraumatic reactions are severe. Early psychosocial interventions may protect perinatal women from PTSD-like symptoms after a wildfire.

Interhemispheric modulations of motor outputs by the rostral and caudal forelimb areas in rats.

In rats, forelimb movements are evoked from two cortical regions, the caudal and rostral forelimb areas (CFA and RFA, respectively). These areas are densely interconnected and RFA induces complex and powerful modulations of CFA outputs. CFA and RFA also have interhemispheric connections, and these areas from both hemispheres send projections to common targets along the motor axis, providing multiple potential sites of interactions for movement production. Our objective was to characterize how CFA and RFA in one hemisphere can modulate motor outputs of the opposite hemisphere. To do so, we used paired-pulse protocols with intracortical microstimulation techniques (ICMS), while recording electromyographic (EMG) activity of forelimb muscles in sedated rats. A subthreshold conditioning stimulation was applied in either CFA or RFA in one hemisphere simultaneously or before a suprathreshold test stimulation in either CFA or RFA in the opposite hemisphere. Both CFA and RFA tended to facilitate motor outputs with short (0-2.5 ms) or long (20-35 ms) delays between the conditioning and test stimuli. In contrast, they tended to inhibit motor outputs with intermediate delays, in particular 10 ms. When comparing the two areas, we found that facilitatory effects from RFA were more frequent and powerful than the ones from CFA. In contrast, inhibitory effects from CFA on its homolog were more frequent and powerful than the ones from RFA. Our results demonstrate that interhemispheric modulations from CFA and RFA share some similarities but also have clear differences that could sustain specific functions these cortical areas carry for the generation of forelimb movements.NEW & NOTEWORTHY We show that caudal and rostral forelimb areas (CFA and RFA) have distinct effects on motor outputs from the opposite hemisphere, supporting that they are distinct nodes in the motor network of rats. However, the pattern of interhemispheric modulations from RFA has no clear equivalent among premotor areas in nonhuman primates, suggesting they contribute differently to the generation of ipsilateral hand movements. Understanding these interspecies differences is important given the common use of rodent models in motor control and recovery studies.

Modulatory effects of the supplementary motor area on primary motor cortex outputs.

Premotor areas of primates are specialized cortical regions that can contribute to hand movements by modulating the outputs of the primary motor cortex (M1). The goal of the present work was to study how the supplementary motor area (SMA) located within the same hemisphere [i.e., ipsilateral SMA (iSMA)] or the opposite hemisphere [i.e., contralateral (cSMA)] modulate the outputs of M1. We used paired-pulse protocols with intracortical stimulations in sedated capuchin monkeys. A conditioning stimulus in iSMA or cSMA was delivered simultaneously or before a test stimulus in M1 with different interstimulus intervals (ISIs) while electromyographic activity was recorded in hand and forearm muscles. The pattern of modulation from iSMA and cSMA shared some clear similarities. In particular, both areas predominantly induced facilitatory effects on M1 outputs with shorter ISIs and inhibitory effects with longer ISIs. However, the incidence and strength of facilitatory effects were greater for iSMA than cSMA. We then compared the pattern of modulatory effects from SMA to the ones from the dorsal and ventral premotor cortexes (PMd and PMv) collected in the same series of experiments. Among premotor areas, the impact of SMA on M1 outputs was always weaker than the one of either PMd or PMv, and this was regardless of the hemisphere, or the ISI, tested. These results show that SMA exerts a unique set of modulations on M1 outputs, which could support its specific function for the production of hand movements.NEW & NOTEWORTHY We unequivocally isolated stimulation to either the ipsilateral or contralateral supplementary motor area (SMA) using invasive techniques and compared their modulatory effects on the outputs of primary motor cortex (M1). Modulations from both SMAs shared many similarities. However, facilitatory effects evoked from ipsilateral SMA were more common and more powerful. This pattern differs from the ones of other premotor areas, which suggests that each premotor area makes unique contributions to the production of motor outputs.

H-reflex modulation preceding changes in soleus EMG activity during balance perturbation.

When balance is compromised, postural strategies are induced to quickly recover from the perturbation. However, neuronal mechanisms underlying these strategies are not fully understood. Here, we assessed the amplitude of the soleus (SOL) H-reflex during forward and backward tilts of the support surface during standing (n = 15 healthy participants). Electrical stimulation of the tibial nerve was applied randomly before platform tilt (control) and 0, 25, 50, 75, 100 or 200 ms after tilt onset. During backward tilt, a significant decrease in H-reflex amplitude was observed at 75, 100 and 200 ms. The onset of the decreased H-reflex amplitude significantly preceded the onset of the SOL EMG decrease (latency: 144 ± 16 ms). During forward tilt, the amplitude of the H-reflex increased at 100 and 200 ms after tilt onset. The onset of H-reflex increase did not occur significantly earlier than the onset of the SOL EMG increase (127 ± 5 ms). An important inter-subject variability was observed for the onset of H-reflex modulation with respect to EMG response for each direction of tilt, but this variability could not be explained by the subject's height. Taken together, the results establish the time course of change in SOL H-reflex excitability and its relation to the increase and decrease in SOL EMG activity during forward and backward tilts. The data presented here also suggest that balance mechanisms may differ between forward and backward tilts.

The 5-HTTLPR polymorphism of the serotonin transporter gene and child's sex moderate the relationship between disaster-related prenatal maternal stress and autism spectrum disorder traits: The QF2011 Queensland flood study.

The 5-HTTLPR polymorphism of the serotonin transporter has been shown to play a role in autism spectrum disorders (ASD). Moreover, disaster-related prenatal maternal stress (PNMS) has also been shown to be associated with ASD. However, no study to date has examined whether these two factors, either individually or in combination, are predictive of ASD traits in the same sample. We hypothesized that children, particularly boys, with the LL genotype exposed to high levels of disaster-related PNMS would exhibit higher levels of ASD traits compared to boys with the LS or SS genotypes and girls regardless of genotype. Genotype and ASD levels obtained using the Australian normed Autism Spectrum Rating Scales - Short Form were available for 105 30-month-old children exposed to varying levels of PNMS following the 2011 Queensland Flood. For boys, higher ASD traits were associated with the 5-HTTLPR LL genotype in combination with either a negative maternal appraisal of the flood, or high levels of maternal composite subjective stress, PSTD-like or peritraumatic dissociation symptoms. For girls, maternal peritraumatic dissociation levels in combination with the 5-HTTLPR LS or SS genotype were associated with higher ASD traits. The present findings are the first to demonstrate that children's genotype moderates effects of disaster-related PNMS on ASD traits, with different pattern according to child sex.

Regional brain volume changes following chronic antipsychotic administration are mediated by the dopamine D2 receptor.

BACKGROUND: Neuroanatomical alterations are well established in patients suffering from schizophrenia, however the extent to which these changes are attributable to illness, antipsychotic drugs (APDs), or their interaction is unclear. APDs have been extremely effective for treatment of positive symptoms in major psychotic disorders. Their therapeutic effects are mediated, in part, through blockade of D2-like dopamine (DA) receptors, i.e. the D2, D3 and D4 dopamine receptors. Furthermore, the dependency of neuroanatomical change on DA system function and D2-like receptors has yet to be explored. METHODS: We undertook a preclinical longitudinal study to examine the effects of typical (haloperidol (HAL)) and atypical (clozapine (CLZ)) APDs in wild type (WT) and dopamine D2 knockout (D2KO) mice over 9-weeks using structural magnetic resonance imaging (MRI). RESULTS: Chronic typical APD administration in WT mice was associated with reductions in total brain (p = 0.009) and prelimbic area (PL) (p = 0.02) volumes following 9-weeks, and an increase in striatal volume (p = 0.04) after six weeks. These APD-induced changes were not present in D2KOs, where, at baseline, we observed significantly smaller overall brain volume (p < 0.01), thinner cortices (q < 0.05), and enlarged striata (q < 0.05). Stereological assessment revealed increased glial density in PL area of HAL treated wild types. Interestingly, in WT and D2KO mice, chronic CLZ administration caused more limited changes in brain structure. CONCLUSIONS: Our results present evidence for the role of D2 DA receptors in structural alterations induced by the administration of the typical APD HAL and that chronic administration of CLZ has a limited influence on brain structure.

Disaster in pregnancy: midwifery continuity positively impacts infant neurodevelopment, QF2011 study.

BACKGROUND: Research shows that continuity of midwifery carer in pregnancy improves maternal and neonatal outcomes. This study examines whether midwifery group practice (MGP) care during pregnancy affects infant neurodevelopment at 6-months of age compared to women receiving standard hospital maternity care (SC) in the context of a natural disaster. METHODS: This prospective cohort study included 115 women who were affected by a sudden-onset flood during pregnancy. They received one of two models of maternity care: MGP or SC. The women's flood-related objective stress, subjective reactions, and cognitive appraisal of the disaster were assessed at recruitment into the study. At 6-months postpartum they completed the Ages and Stages Questionnaire (ASQ-3) on their infants' communication, fine and gross motor, problem solving, and personal-social skills. RESULTS: Greater maternal objective and subjective stress predicted worse infant outcomes. Even when controlling for maternal stress from the flood, infants of mothers who were in the MGP model of maternity care performed better than infants of mothers in SC on two of the five ASQ-3 domains (fine motor and problem solving) at 6-months of age. Furthermore, infants in the SC model were more likely to be identified as at risk for delayed development on these domains than infants in the MGP model of care. CONCLUSIONS: Continuity of midwifery care has positive effects on infant neurodevelopment when mothers experience disaster-related stress in pregnancy, with significantly better outcomes on two developmental domains at 6 months compared to infants whose mothers received standard hospital care.

The role of prenatal maternal stress in the development of childhood anxiety symptomatology: The QF2011 Queensland Flood Study.

It is possible that findings suggesting a link between prenatal maternal stress (PNMS) and anxiety symptoms in offspring are confounded by postnatal and/or shared mother-child heritability effects. Following exposure to a natural disaster, the Queensland Flood Study investigated the unique and additive effects of various types of disaster-related PNMS (objective hardship, cognitive appraisal, and subjective distress) on childhood anxiety symptomatology (internalizing and/or anxiety symptom measures). Timing of flood exposure during pregnancy and child sex were examined as potential moderators. After controlling for maternal psychosocial factors, greater objective hardship as a result of the floods was significantly associated with greater anxiety symptoms (N = 114) and marginally associated with greater internalizing behaviors (N = 115). Earlier timing of the flood in pregnancy was associated with greater anxiety symptoms. No such associations were found between any PNMS measure and teacher-rated child internalizing behaviors (N = 90). Sex and timing did not moderate associations. Our findings suggest that, in isolation, increased maternal hardship due to exposure to an independent stressor, during pregnancy, may have a programming effect on childhood anxiety symptoms.

Testosterone-cortisol dissociation in children exposed to prenatal maternal stress, and relationship with aggression: Project Ice Storm.

Prenatal maternal stress (PNMS) has been associated with postnatal behavioral alterations that may be partly explained by interactions between the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes. Yet it remains unclear whether PNMS leads to enduring HPA-HPG alterations in the offspring, and whether HPA-HPG interactions can impact behavior during development, in particular levels of aggression in childhood. Here we investigated the relationship between a marker for HPG axis function (baseline testosterone) and a marker for HPA axis response (cortisol area under the curve) in 11½-year-olds whose mothers were exposed to the 1998 Quebec ice storm during pregnancy (n = 59 children; 31 boys, 28 girls). We examined (a) whether the degree of objective or subjective PNMS regulates the testosterone-cortisol relationship at age 11½, and (b) whether this testosterone-cortisol relationship is associated with differences in aggressive behavior. We found that, at lower levels of subjective PNMS, baseline testosterone and cortisol reactivity were positively correlated; in contrast, there was no relationship between these hormones at higher levels of subjective PNMS. Cortisol response moderated the relationship between testosterone and aggression. These results support the notion PNMS may explain variance in fetal HPA-HPG interactions, and that these interactions may be associated with aggressive behavior in late childhood.

The impact of maternal flood-related stress and social support on offspring weight in early childhood.

The current study examined the moderating role of social support in the association between prenatal maternal stress (PNMS) and childhood body mass index (BMI) in the context of the Iowa floods of 2008. In addition, the mediating role of offspring birthweight was examined in the association between PNMS and childhood BMI. We recruited women from eastern Iowa who were pregnant in 2008 when disastrous floods occurred. Self-report measures of PNMS and cognitive appraisal of the flood's consequences were obtained shortly after the disaster. Social support was assessed during pregnancy. Offspring anthropometric measures were collected at birth and 30 months. Moderated mediation results indicated that greater PNMS predicted greater BMI at age 30 months through effects on higher birthweight as a mediator, but only for participants with low social support. High social support (satisfaction or number) buffered the effect of PNMS or a negative appraisal of the flood on birthweight. The combination of high PNMS or a negative appraisal of the flood's consequences and low social support resulted in higher offspring birthweight, which predicted greater BMI at 30 months. Providing strong social support to pregnant women following a stressor might buffer the effects of PNMS on offspring birthweight and later obesity.

Continuity of midwifery carer moderates the effects of prenatal maternal stress on postnatal maternal wellbeing: the Queensland flood study.

Poor postnatal mental health is a major public health issue, and risk factors include experiencing adverse life events during pregnancy. We assessed whether midwifery group practice, compared to standard hospital care, would protect women from the negative impact of a sudden-onset flood on postnatal depression and anxiety. Women either received midwifery group practice care in pregnancy, in which they were allocated a primary midwife who provided continuity of care, or they received standard hospital care provided by various on-call and rostered medical staff. Women were pregnant when a sudden-onset flood severely affected Queensland, Australia, in January 2011. Women completed questionnaires on their flood-related hardship (objective stress), emotional reactions (subjective stress), and cognitive appraisal of the impact of the flood. Self-report assessments of the women's depression and anxiety were obtained during pregnancy, at 6 weeks and 6 months postnatally. Controlling for all main effects, regression analyses at 6 weeks postpartum showed a significant interaction between maternity care type and objective flood-related hardship and subjective stress, such that depression scores increased with increasing objective and subjective stress with standard care, but not with midwifery group practice (continuity), indicating a buffering effect of continuity of midwifery carer. Similar results were found for anxiety scores at 6 weeks, but only with subjective stress. The benefits of midwifery continuity of carer in pregnancy extend beyond a more positive birth experience and better birthing and infant outcomes, to mitigating the effects of high levels of stress experienced by women in the context of a natural disaster on postnatal mental health.

A trajectory analysis of childhood motor development following stress in pregnancy: The QF2011 flood study.

This prospective, longitudinal cohort study examined the effects of flood-related stress in pregnancy on the trajectory of children's motor development; and the moderating effects of gestational timing of the flood or sex of the child. Women who were pregnant during a severe flood reported on their objective flood-related experiences, emotional reactions, and cognitive appraisal of the disaster. At 2-, 6-, 16-months, 2½- and 4-years postpartum, mothers' assessed their children's fine and gross motor development using the Ages and Stages-3 Questionnaire. High objective flood-exposure, or a negative appraisal, especially in later pregnancy, predicted poorer gross motor skills which rapidly improved across early childhood. Children's fine motor skill was influenced by the sex of the child with improvements in girls' fine motor skills over time, but not boys'. This demonstrates that stress in pregnancy has enduring influences on gross, but not fine, motor skills. Results are discussed in relation to fetal programming and stress appraisal theory.

Interhemispheric interactions between trunk muscle representations of the primary motor cortex.

Unilateral arm movements require trunk stabilization through bilateral contraction of axial muscles. Interhemispheric interactions between primary motor cortices (M1) could enable such coordinated contractions, but these mechanisms are largely unknown. Using transcranial magnetic stimulation (TMS), we characterized interhemispheric interactions between M1 representations of the trunk-stabilizing muscles erector spinae at the first lumbar vertebra (ES L1) during a right isometric shoulder flexion. These interactions were compared with those of the anterior deltoid (AD), the main agonist in this task, and the first dorsal interosseous (FDI). TMS over the right M1 elicited ipsilateral silent periods (iSP) in all three muscles on the right side. In ES L1, but not in AD or FDI, ipsilateral motor evoked potential (iMEP) could precede the iSP or replace it. iMEP amplitude was not significantly different whether ES L1 was used to stabilize the trunk or was voluntarily contracted. TMS at the cervicomedullary junction showed that the size of cervicomedullary evoked potential was unchanged during the iSP but increased during iMEP, suggesting that the iSP, but not the iMEP, is due to intracortical mechanisms. Using a dual-coil paradigm with two coils over the left and right M1, interhemispheric inhibition could be evoked at interstimulus intervals of 6 ms in ES L1 and 8 ms in AD and FDI. Together, these results suggest that interhemispheric inhibition is dominant when axial muscles are involved in a stabilizing task. The ipsilateral facilitation could be evoked by ipsilateral or subcortical pathways and could be used depending on the role axial muscles play in the task.NEW & NOTEWORTHY The mechanisms involved in the bilateral coordination of axial muscles during unilateral arm movement are poorly understood. We thus investigated the nature of interhemispheric interactions in axial muscles during arm motor tasks in healthy subjects. By combining different methodologies, we showed that trunk muscles receive both inhibitory and facilitatory cortical outputs during activation of arm muscles. We propose that inhibition may be conveyed mainly through interhemispheric mechanisms and facilitation by subcortical mechanisms or ipsilateral pathways.