Overground gait training promotes functional recovery and cortical neuroplasticity in an incomplete spinal cord injury model.

ABSTRACT

AIM: Evidence suggests that task-specific gait training improves locomotor impairments in people with incomplete spinal cord injury (SCI); however, plastic changes in brain areas remain poorly understood. The aim of this study was to examine the possible effects of a task-specific overground gait training on locomotor recovery and neuroplasticity markers in the cortex, cerebellum, and lumbar spinal cord in an experimental model of incomplete-SCI. MAIN METHODS: Using a blind, basic experimental design, 24 adult Wistar rats underwent a surgical procedure and were allocated into sham, non-trained SCI (SCI), and trained SCI (Tr-SCI) groups. On postoperative day 14, trained animals started a 4-week overground gait training program. All groups were subjected to weekly assessment of locomotor recovery of the hind limbs. On postoperative day 40, brain and lumbar spinal cord structures were dissected and processed for biochemical analysis of the synaptophysin, microtubule-associated protein 2 (MAP-2), and brain-derived neurotrophic factor (BDNF). KEY FINDINGS: Tr-SCI group showed greater locomotor function recovery compared with non-trained SCI from the postoperative day 21 (p < 0.05). The training was able to improve the neuroplasticity markers synaptophysin, MAP-2, and BDNF expressions in motor cortex (p < 0.05), but not in the cerebellum and in the spinal cord for trained SCI group compared to non-trained. SIGNIFICANCE: Task-specific overground gait training improves locomotor recovery in a rat model of incomplete thoracic-SCI. Furthermore, training promotes motor cortex plasticity, evidenced for increasing expression of the neuroplasticity markers that may support the functional recovery.