Altered Amygdala Development and Fear Processing in Prematurely Born Infants

Area of Science:

• Neuroscience
• Developmental Biology
• Pediatrics

Background:

• Premature birth increases the risk of developmental and behavioral disabilities.
• Cerebral abnormalities are linked to later behavioral issues, but amygdala development in preterm infants is understudied.
• Early amygdala development in humans following premature birth requires further investigation.

Purpose of the Study:

• To compare amygdala volumes in very preterm infants versus term-born infants at term equivalent age (TEA).
• To investigate the relationship between amygdala volumes in preterm infants and their fear responses at 12 months using the Laboratory Temperament Assessment Battery (Lab-TAB).

Main Methods:

• Magnetic resonance imaging (MRI) was used to manually delineate amygdala volumes in 81 infants (preterm and term-born) at TEA.
• Automated segmentation was performed to assess gray matter, white matter, and cerebrospinal fluid (CSF) volumes in 66 infants.
• Behavioral assessments of fear responses were conducted using the Lab-TAB in 42 preterm infants at 12 months.

Main Results:

• Preterm infants exhibited significantly smaller amygdala volumes compared to term-born infants at TEA.
• White matter volumes were reduced, and CSF volumes were increased in preterm infants.
• Smaller amygdala volumes correlated with a higher intensity of escape response to a fearsome toy in preterm infants.

Conclusions:

• Premature birth is associated with reduced amygdala and white matter volumes at TEA.
• Altered amygdala development may be linked to white matter connectivity changes in preterm infants.
• These brain alterations may influence infants' capacity for fear processing.