Change in neuroplasticity-related proteins in response to acute activity-based therapy in persons with spinal cord injury

Abstract

Background: Activity-based therapy (ABT) focuses on regaining motor and sensory function below the level of the lesion in persons with a spinal cord injury (SCI). This is accomplished through repetitive training of specific motor tasks. Research has shown that ABT may increase neuroplasticity in the rat and human spinal cord. Objective: The primary aim of this study was to examine acute alterations in neuroplasticity-related proteins during ABT in persons with SCI. Methods: Volunteers were current participants in an ABT program and consisted of 12 men and 3 women (age, 31.8 ± 10.9 years) with chronic SCI (injury duration, 63.9 ± 54.4 months). A single 2-hour bout of ABT consisted of standing load bearing, body weight-supported treadmill training, whole body vibration, and functional electrical stimulation. Blood samples were obtained at baseline and immediately after completion of each modality to determine serum levels of brain-derived neurotrophic factor (BDNF), prolactin, and cortisol. Results: One-way analysis of variance (ANOVA) with repeated measures was used to examine differences in proteins over time. Results revealed baseline levels of BDNF (2.37 ± 1.41 ng/mL) that were lower than previous research has demonstrated in persons with SCI. No change in BDNF or cortisol was found, although prolactin was significantly reduced in response to ABT. Conclusion: Despite the length of the bout, acute changes in BDNF were not observed. Whether different intensities or modalities of ABT may promote acute increases in serum BDNF in individuals with SCI remains to be determined and further study is merited. © 2014 Thomas Land Publishers, Inc.