Premature birth may do more than interrupt brain development – it may fundamentally alter how the cerebellum matures into early childhood, according to a new study. The findings reveal how the timing of birth shapes brain cell development and neural connections, offering new insight into the lasting neurodevelopmental effects of prematurity. The cerebellum undergoes its most rapid period of growth between 24 and 40 weeks of gestation, making premature birth a potential disruption to a critical phase of brain development. Although early birth is known to alter cerebellar growth and neurodevelopment, the underlying molecular and cellular mechanisms remain poorly understood. To address this gap, Georgios Sanidas and colleagues studied living and postmortem infants, some of whom were born prematurely, while others were born at term. They combined postmortem cerebellar tissue analysis with brain imaging and developmental assessments.
Using spatial gene-expression profiling and deep-learning-based tissue analysis, Sanidas et al. mapped cerebellar development across a broad range of gestational ages. The analysis revealed that premature birth reshapes the cerebellum's developmental trajectory, with the timing of birth influencing how distinct brain cell populations mature even after infants reach the same postmenstrual age as those born at term. According to the authors, premature development involves disrupted coordination between Purkinje and granule cells, potentially impairing the refinement of neural connections despite the cerebellum retaining its overall structure. These findings suggest that prematurity does not simply interrupt normal development or expose the brain to injury; it alters the biological conditions under which maturation unfolds. Although the long-term persistence of these changes remains uncertain, the authors argue that the findings offer a framework for understanding how early birth influences later motor and cognitive outcomes, which may help guide the timing of future interventions. "Although the preterm human infant may follow two calendars, one for cerebellar physical growth and one for cerebellar cell and molecular maturation, the findings of Sanidas et al. show that neither captures the true complexity of brain health at the time, nor what it means for the child years later," write Molly Kelly-Goss and Elizabeth Crouch in a related Perspective.
