Prenatal lead exposure impacts cross-hemispheric and long-range connectivity in the human fetal brain

• Published in: NeuroImage (Orlando, Fla.) Vol. 191; pp. 186 - 192
• Main Authors: Thomason, Moriah E., Hect, Jasmine L., Rauh, Virginia A., Trentacosta, Christopher, Wheelock, Muriah D., Eggebrecht, Adam T., Espinoza-Heredia, Claudia, Burt, S. Alexandra
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2019; Elsevier Limited
• Subjects: Age; Animal cognition; Brain; Brain - drug effects; Brain - pathology; Cognitive ability; Connectivity; Consent; Cortex (cingulate); Female; Fetal; Fetus; Fetuses; Functional magnetic resonance imaging; Humans; Lead; Lead - adverse effects; Lead poisoning; Lead Poisoning, Nervous System, Childhood - pathology; Magnetic Resonance Imaging - methods; Medical screening; Mothers; MRI; Nervous system; Neural networks; Neural Pathways - drug effects; Neural Pathways - pathology; NMR; Nuclear magnetic resonance; Prefrontal cortex; Pregnancy; Prenatal; Prenatal Diagnosis; Prenatal experience; Prenatal Exposure Delayed Effects - etiology; Prenatal Exposure Delayed Effects - pathology; Resting-state; Detroit Michigan; United States > US; Michigan; Prenatal; Brain; MRI; Lead; Connectivity; Resting-state; Fetal
• DOI: 10.1016/j.neuroimage.2019.02.017
• ISSN: 1053-8119

Lead represents a highly prevalent metal toxicant with potential to alter human biology in lasting ways. A population segment that is particularly vulnerable to the negative consequences of lead exposure is the human fetus, as exposure events occurring before birth are linked to varied and long-ranging negative health and behavioral outcomes. An area that has yet to be addressed is the potential that lead exposure during pregnancy alters brain development even before an individual is born. Here, we combine prenatal lead exposure information extracted from newborn bloodspots with the human fetal brain functional MRI data to assess whether neural network connectivity differs between lead-exposed and lead-naïve fetuses. We found that neural connectivity patterns differed in lead-exposed and comparison groups such that fetuses that were not exposed demonstrated stronger age-related increases in cross-hemispheric connectivity, while the lead-exposed group demonstrated stronger age-related increases in posterior cingulate cortex (PCC) to lateral prefrontal cortex (PFC) connectivity. These are the first results to demonstrate metal toxicant-related alterations in human fetal neural connectivity. Remarkably, the findings point to alterations in systems that support higher-order cognitive and regulatory functions. Objectives for future work are to replicate these results in larger samples and to test the possibility that these alterations may account for significant variation in future child cognitive and behavioral outcomes. •In humans, prenatal exposure to lead relates to connectivity of large-scale fetal brain systems.•Age-related strengthening of insular/temporal cross-hemispheric functional connectivity was stronger in fetuses that did not appear to have been exposed to lead.•Fetuses exposed to lead showed age-related strengthening of lateral prefrontal to posterior cingulate functional connectivity.