305 - Timing and Intensity of Sensory-Motor Therapies Shapes Cerebellar-Mediated Motor and Social Outcomes After Prematurity-Related Insults

Publication Number: 4299.305

Gabriele Simonti, Children's National Health System, Washington, DC, United States; Robinson Vidva, Children's National Health System, Silver Spring, MD, United States; Georgios Sanidas, Children National Hospital, Washington, DC, United States; Nora Wolff, Children's National Research Institute, Washington, DC, United States; Maria Triantafyllou, Children's National Health System, Washington, DC, United States; Courtney Lowe, Children's National Health System, Washington, DC, United States; Javid Ghaemmaghami, University of Michigan Medical School, Ann Arbo, MI, United States; Ioannis Koutroulis, Children's National Health System, Washington, DC, United States; Vittorio Gallo, Seattle Childrens Hospital, Seattle, WA, United States; Panagiotis Kratimenos, Children's National Health System, Washington, DC, United States

Background: Preterm birth interrupts a critical period of cerebellar maturation, when sensory and motor experiences shape lifelong neurodevelopmental trajectories. Early interventions such as physical therapy (PT) and environmental enrichment (EE) are commonly used in neonatal care to promote neuroplasticity. However, how their timing, sequence, and intensity influence the immature brain remains unclear.

Objective: Clinical observations suggest that excessive stimulation may destabilize developing circuits, underscoring the need to define thresholds that distinguish adaptive from disruptive experiences.

Design/Methods: Using a mouse model combining maternal immune activation (MIA) and neonatal hypoxia (Hx), two major prematurity-related perinatal factors, we examined how early structured motor rehabilitation (PT), sensory-motor enrichment (EE), or their combination affect cerebellar-dependent motor functions and behavioral outcomes. Motor learning was assessed with ErasmusLadder, and social behavior with a three-chamber interaction task coupled to a novel proximity index.

Results: Behavioral assays revealed marked variability in social versus non-social engagement across groups, reflecting unstable social organization in MIA+Hx mice. PT normalized these patterns, restoring consistent social preference and locomotor activity to control levels. During open-field exploration, PT rebalanced movement toward deliberate, evenly distributed exploration, whereas combined PT+EE exposure induced excessive, high-velocity activity resembling hyperactive or ADHD-like behavior. Cerebellar assessments confirmed that dual exposure impaired motor coordination and associative motor learning, suggesting that overstimulation disrupts cerebellar circuit function. In contrast, PT alone improved both metrics, reinforcing its stabilizing effect on motor-cognitive integration. Unsupervised kinematic clustering (B-SOiD) during direct social interaction revealed that motor improvements shape social interactions: PT reinstated flexible motor motifs linked to structured social engagement, whereas PT+EE produced fragmented, repetitive movements.

Conclusion(s): These findings identify the timing, sequence, and intensity of stimulation as critical determinants of cerebellar-driven motor and social outcomes. Graded, structured input through PT stabilizes developing circuits, while excessive multimodal stimulation disrupts them. These data provide a framework to identify the most beneficial sensory and motor therapeutic approach in preterm infants, while reducing the risk of overstimulation in the developing brain.

Figure 1
(A) Experimental design showing timing of maternal immune activation (MIA), postnatal hypoxia (Hx), and subsequent exposure to physical therapy (PT), environmental enrichment (EE), or their combination (PT+EE). (B) Schematic of the three-chamber sociability test with spatial heatmaps illustrating exploratory trajectories. (C) Time spent interacting with a stranger mouse, a novel object, or exploring indicates reduced social engagement and increased variability in double-hit (DH) animals, normalized by PT but not EE. (D) Heatmap of chamber transitions showing reduced exploratory movement in DH mice and partial restoration following PT. (E) Quantification of active exploratory time and average velocity during open-field exploration reveals that PT restores balanced locomotor behavior, whereas dual PT+EE exposure induces hyperactivity, suggesting overstimulation effects on motor regulation.

Figure 2
(A) Representative frames from the three-chamber social assay during direct social contact. (B) Schematic of pose estimation and B-SOiD-based clustering used to extract and classify fine-grained movement motifs. (C) Example of approach-related clusters capturing distinct social engagement kinematics, including forward approach, turning, and exploration. (D) Kinematic transition networks depicting the temporal organization of motor motifs during direct social behavior. Double-hit (DH) mice show reduced and fragmented transitions, whereas physiotherapy (PT) restores motor diversity and coordination. Environmental enrichment (EE) alone minimally improves motor organization, while dual PT+EE exposure further reduces connectivity, indicating overstimulation-induced restriction of interactive movement patterns.