Associations of age and sex with brain volumes and asymmetry in 2–5-week-old infants

Abstract

Information on normal brain structure and development facilitates the recognition of abnormal developmental trajectories and thus needs to be studied in more detail. We imaged 68 healthy infants aged 2–5 weeks with high-resolution structural MRI (magnetic resonance imaging) and investigated hemispheric asymmetry as well as the associations of various total and lobar brain volumes with infant age and sex. We found similar hemispheric asymmetry in both sexes, seen as larger volumes of the right temporal lobe, and of the left parietal and occipital lobes. The degree of asymmetry did not vary with age. Regardless of controlling for gestational age, gray and white matter had different age-related growth patterns. This is a reflection of gray matter growth being greater in the first years, while white matter growth extends into early adulthood. Sex-dependent differences were seen in gray matter as larger regional absolute volumes in males and as larger regional relative volumes in females. Our results are in line with previous studies and expand our understanding of infant brain development.

Newborn amygdalar volumes are associated with maternal prenatal psychological distress in a sex-dependent way

“…found a sex-by-depressive symptom interaction in the middle temporal cortex: female children exposed to maternal PPD had a thinner cortex than males, while a more negative correlation between postpartum EPDS scores and diffusivity was observed in males ( Lebel et al, 2016 ). This finding further highlights sexual dimorphism in brain structures, beyond the dimorphism seen in normative brain development ( Bakker, 2018 , Blakemore et al, 2010 , Lehtola et al, 2019 , Lenroot et al, 2007 ). Evidently, large individual variation exists in responses to stress based upon genetic background ( Rice et al, 2010 ), as well as intrinsic and extrinsic environmental background ( McEwen, 2010 ), which is further modified by hormonal influences, including changes in HPA-axis activity and sex hormone levels.…”

“…Total number of slices was 176. A detailed description of the scanning protocol is provided in a previous publication by the same research team ( Lehtola et al, 2019 ).…”

Newborn left amygdala volume associates with attention disengagement from fearful faces at eight months

“…The 3D T1 MPRAGE was acquired in sagittal plane with a TR of 1900 ms, TE of 3.26 ms, inversion time (TI) of 900 ms, and flip angle (FA) of 9 degrees. A more detailed description of the scanning protocol is provided in our prior reports ( Lehtola et al, 2019 ; Tuulari et al, 2019 ).…”

Newborn white matter microstructure moderates the association between maternal postpartum depressive symptoms and infant negative reactivity

“…The scans were performed in the Medical Imaging Centre of Turku University Hospital in a family–friendly manner as previously described ( Lehtola et al., 2019 ). MRI scans were conducted on a Siemens Magnetom Verio 3 T scanner (Siemens Medical Solutions, Erlangen, Germany) using a 12-element Head Matrix coil.…”