Maturation of Sensori-Motor Functional Responses in the Preterm Brain

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Pediatric Neurology

Background:

• Preterm birth increases risks for conditions like cerebral palsy, highlighting the critical period for sensorimotor system development.
• Limited understanding exists regarding cortical sensorimotor function maturation, experience-dependent influences, and its role in spontaneous motor behavior during this sensitive developmental window.

Purpose of the Study:

• To systematically characterize the spatial and temporal maturation of sensorimotor functional brain activity in infants.
• To investigate the influence of experience on sensorimotor development.
• To explore the role of sensorimotor function in spontaneous motor behavior.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) in 57 infants (30 + 2 to 43 + 2 weeks postmenstrual age).
• Employed a custom-made robotic stimulation device for induced wrist movements.
• Analyzed blood oxygen level-dependent (BOLD) responses to both induced and spontaneous movements.

Main Results:

• Consistent sensorimotor functional responses observed in the contralateral (left) primary somatosensory and motor cortices following right wrist movements.
• Demonstrated a maturational trend towards faster, higher amplitude, and more spatially dispersed functional responses.
• Observed increasing integration of the ipsilateral hemisphere and sensorimotor associative areas, with interhemispheric functional connectivity linked to ex-utero exposure.

Conclusions:

• Sensorimotor brain activity undergoes significant maturation from preterm to term equivalent age.
• Experience-dependent mechanisms appear to influence the development of interhemispheric functional connectivity.
• The mature sensorimotor functional response pattern observed in adults is established by term equivalent age.