Preterm delivery disrupts the developmental program of the cerebellum

Area of Science:

• Neuroscience
• Developmental Biology
• Pediatrics

Background:

• Rapid human cerebellar development occurs in the third trimester.
• Preterm delivery interrupts this critical in-utero developmental period.
• Understanding ex-utero effects on cerebellar development is crucial.

Purpose of the Study:

• To characterize the impact of preterm delivery on the human cerebellar developmental program.
• To compare cerebellar development in infants born preterm versus those developing in-utero.

Main Methods:

• Age-paired comparison of stillborn (in-utero development) and preterm infants (ex-utero development).
• Quantitative assessment of molecular markers for granule neuron, Purkinje neuron, and Bergmann glia differentiation.
• Analysis of sonic hedgehog signaling pathway expression, vital for cerebellar growth.

Main Results:

• Preterm birth and ex-utero development significantly decreased the thickness of the external granular layer and inner granular layer.
• Increased cell packing density was observed in the external and inner granular layers.
• Reduced Bergmann glial fiber density and decreased sonic hedgehog expression in the Purkinje layer were noted.

Conclusions:

• The developmental trajectory of the human cerebellum is significantly modified by the events following preterm delivery.
• Ex-utero development due to preterm birth impacts key cellular and molecular aspects of cerebellar maturation.
• Findings highlight the vulnerability of the third-trimester cerebellum to environmental changes post-birth.