Maternal depression during pregnancy alters infant subcortical and midbrain volumes.

BACKGROUND: Maternal depression in pregnancy increases the risk for adverse neurodevelopmental outcomes in the offspring. The reason for this is unknown, however, one plausible mechanism may include the impact of maternal antenatal depression on infant brain. Nevertheless, relatively few studies have examined the brain anatomy of infants born to clinically diagnosed mothers. METHODS: A legacy magnetic resonance imaging (MRI) dataset was used to compare regional brain volumes in 3-to-6-month-old infants born to women with a clinically confirmed diagnosis of major depressive disorder (MDD) during pregnancy (n = 31) and a reference sample of infants born to women without a current or past psychiatric diagnosis (n = 33). A method designed for analysis of low-resolution scans enabled examination of subcortical and midbrain regions previously found to be sensitive to the parent-child environment. RESULTS: Compared with infants of non-depressed mothers, infants exposed to maternal antenatal depression had significantly larger subcortical grey matter volumes and smaller midbrain volumes. There was no association between gestational medication exposure and the infant regional brain volumes examined in our sample. LIMITATIONS: Our scanning approach did not allow for an examination of fine-grained structural differences, and without repeated measures of brain volume, it is unknown whether the direction of reported associations are dependent on developmental stage. CONCLUSIONS: Maternal antenatal depression is associated with an alteration in infant brain anatomy in early postnatal life; and that this is not accounted for by medication exposure. However, our study cannot address whether anatomical differences impact on future outcomes of the offspring.

Father-infant interactions and infant regional brain volumes: A cross-sectional MRI study.

Fathers play a crucial role in their children's socio-emotional and cognitive development. A plausible intermediate phenotype underlying this association is father's impact on infant brain. However, research on the association between paternal caregiving and child brain biology is scarce, particularly during infancy. Thus, we used magnetic resonance imaging (MRI) to investigate the relationship between observed father-infant interactions, specifically paternal sensitivity, and regional brain volumes in a community sample of 3-to-6-month-old infants (N = 28). We controlled for maternal sensitivity and examined the moderating role of infant communication on this relationship. T2-weighted MR images were acquired from infants during natural sleep. Higher levels of paternal sensitivity were associated with smaller cerebellar volumes in infants with high communication levels. In contrast, paternal sensitivity was not associated with subcortical grey matter volumes in the whole sample, and this was similar in infants with both high and low communication levels. This preliminary study provides the first evidence for an association between father-child interactions and variation in infant brain anatomy.

Familial risk of autism alters subcortical and cerebellar brain anatomy in infants and predicts the emergence of repetitive behaviors in early childhood.

Autism spectrum disorder (ASD) is a common neurodevelopmental condition, and infant siblings of children with ASD are at a higher risk of developing autistic traits or an ASD diagnosis, when compared to those with typically developing siblings. Reports of differences in brain anatomy and function in high-risk infants which predict later autistic behaviors are emerging, but although cerebellar and subcortical brain regions have been frequently implicated in ASD, no high-risk study has examined these regions. Therefore, in this study, we compared regional MRI volumes across the whole brain in 4-6-month-old infants with (high-risk, n = 24) and without (low-risk, n = 26) a sibling with ASD. Within the high-risk group, we also examined whether any regional differences observed were associated with autistic behaviors at 36 months. We found that high-risk infants had significantly larger cerebellar and subcortical volumes at 4-6-months of age, relative to low-risk infants; and that larger volumes in high-risk infants were linked to more repetitive behaviors at 36 months. Our preliminary observations require replication in longitudinal studies of larger samples. If correct, they suggest that the early subcortex and cerebellum volumes may be predictive biomarkers for childhood repetitive behaviors. Autism Res 2019, 12: 614-627. © 2019 The Authors. Autism Research published by International Society for Autism Research published byWiley Periodicals, Inc. LAY SUMMARY: Individuals with a family history of autism spectrum disorder (ASD) are at risk of ASD and related developmental difficulties. This study revealed that 4-6-month-old infants at high-risk of ASD have larger cerebellum and subcortical volumes than low-risk infants, and that larger volumes in high-risk infants are associated with more repetitive behaviors in childhood.

Mother-infant interactions and regional brain volumes in infancy: an MRI study.

It is generally agreed that the human brain is responsive to environmental influences, and that the male brain may be particularly sensitive to early adversity. However, this is largely based on retrospective studies of older children and adolescents exposed to extreme environments in childhood. Less is understood about how normative variations in parent-child interactions are associated with the development of the infant brain in typical settings. To address this, we used magnetic resonance imaging to investigate the relationship between observational measures of mother-infant interactions and regional brain volumes in a community sample of 3- to 6-month-old infants (N = 39). In addition, we examined whether this relationship differed in male and female infants. We found that lower maternal sensitivity was correlated with smaller subcortical grey matter volumes in the whole sample, and that this was similar in both sexes. However, male infants who showed greater levels of positive communication and engagement during early interactions had smaller cerebellar volumes. These preliminary findings suggest that variations in mother-infant interaction dimensions are associated with differences in infant brain development. Although the study is cross-sectional and causation cannot be inferred, the findings reveal a dynamic interaction between brain and environment that may be important when considering interventions to optimize infant outcomes.

Subthalamic nucleus deep brain stimulation induces impulsive action when patients with Parkinson's disease act under speed pressure.

The subthalamic nucleus (STN) is proposed to modulate response thresholds and speed-accuracy trade-offs. In situations of conflict, the STN is considered to raise response thresholds, allowing time for the accumulation of information to occur before a response is selected. Conversely, speed pressure is thought to reduce the activity of the STN and lower response thresholds, resulting in fast, errorful responses. In Parkinson's disease (PD), subthalamic nucleus deep brain stimulation (STN-DBS) reduces the activity of the nucleus and improves motor symptoms. We predicted that the combined effects of STN stimulation and speed pressure would lower STN activity and lead to fast, errorful responses, hence resulting in impulsive action. We used the motion discrimination 'moving-dots' task to assess speed-accuracy trade-offs, under both speed and accuracy instructions. We assessed 12 patients with PD and bilateral STN-DBS and 12 age-matched healthy controls. Participants completed the task twice, and the patients completed it once with STN-DBS on and once with STN-DBS off, with order counterbalanced. We found that STN stimulation was associated with significantly faster reaction times but more errors under speed instructions. Application of the drift diffusion model showed that stimulation resulted in lower response thresholds when acting under speed pressure. These findings support the involvement of the STN in the modulation of speed-accuracy trade-offs and establish for the first time that speed pressure alone, even in the absence of conflict, can result in STN stimulation inducing impulsive action in PD.