Neural Regeneration Research, 2021 · DOI: https://doi.org/10.4103/1673-5374.295346 · Published: April 1, 2021
Spinal cord injury (SCI) disrupts communication between the brain and body, but how the motor cortex (the brain area controlling movement) changes after SCI isn't fully understood. This study explores how synapses, the connections between brain cells, are reorganized in the motor cortex of mice after a spinal cord injury. The researchers created a mouse model of spinal cord injury and then monitored the postsynaptic dendritic spines (receiving ends of synapses) and presynaptic axonal boutons (sending ends of synapses) in the motor cortex. They found that spinal cord injury leads to remodeling of dendritic spines on both sides of the motor cortex. The study suggests that after spinal cord injury, the motor cortex undergoes synaptic remodeling, primarily affecting the receiving ends (dendritic spines) of synapses rather than the sending ends (axonal boutons). This remodeling process involves making previously stable spines unstable and forming new spines, although these new spines are fragile.
Understanding synaptic remodeling may inform the development of targeted rehabilitation therapies to promote the formation and stabilization of new spines in the contralateral motor cortex.
The study provides a structural basis for tracking treatment-induced changes in the motor cortex after SCI, potentially allowing for more effective evaluation of therapeutic interventions.
Further investigation into the roles of new and stable spines, as well as the underlying functional regulatory mechanisms, may lead to new targets for SCI treatment.