Biological effects of dosing aerobic exercise and neuromuscular electrical stimulation in rats

Stefania Dalise,Carmelo Chisari,Madeline Gerwig,Loredana Cavalli,Fabrisia Ambrosio,Brendon Wahlberg,Michel Modo,Harmanvir Ghuman

doi:10.1038/s41598-017-11260-7

Abstract

Aerobic exercise (AE) and non-aerobic neuromuscular electric stimulation (NMES) are common interventions used in physical therapy. We explored the dose-dependency (low, medium, high) of these interventions on biochemical factors, such as brain derived neurotrophic growth factor (BDNF), vascular endothelial growth factor-A (VEGF-A), insulin-like growth factor-1 (IGF-1) and Klotho, in the blood and brain of normal rats, as well as a treadmill-based maximum capacity test (MCT). A medium dose of AE produced the most improvement in MCT with dose-dependent changes in Klotho in the blood. A dose-dependent increase of BDNF was evident following completion of an NMES protocol, but there was no improvement in MCT performance. Gene expression in the hippocampus was increased after both AE and NMES, with IGF-1 being a signaling molecule that correlated with MCT performance in the AE conditions, but also highly correlated with VEGF-A and Klotho. Blood Klotho levels can serve as a biomarker of therapeutic dosing of AE, whereas IGF-1 is a key molecule coupled to gene expression of other molecules in the hippocampus. This approach provides a translatable paradigm to investigate the mode and mechanism of action of interventions employed in physical therapy that can improve our understanding of how these factors change under pathological conditions.

Highlights

Aerobic exercise (AE) and neuromuscular electric stimulation (NMES) are common interventions used in physical therapy for peripheral nerve regeneration[1], traumatic brain injury[2, 3], stroke[4, 5], spinal cord injuries[6] and neurodegenerative disease
In the context of AE and NMES, biomarkers of particular interest suggested to be responsive to physical activity include: brain derived neurotrophic factor (BDNF), which is involved in neurogenesis, vascular endothelial growth factor (VEGF)-A involved in angiogenesis, and insulin-like growth factor-1 (IGF-1) promoting growth and maintenance of muscle[21, 22]
A dosing effect of AE was evident in maximum capacity testing (MCT) with a medium dose providing the most significant gain in performance

Summary

Introduction

Aerobic exercise (AE) and neuromuscular electric stimulation (NMES) are common interventions used in physical therapy for peripheral nerve regeneration[1], traumatic brain injury[2, 3], stroke[4, 5], spinal cord injuries[6] and neurodegenerative disease. In the context of AE and NMES, biomarkers of particular interest suggested to be responsive to physical activity include: brain derived neurotrophic factor (BDNF), which is involved in neurogenesis, vascular endothelial growth factor (VEGF)-A involved in angiogenesis, and insulin-like growth factor-1 (IGF-1) promoting growth and maintenance of muscle[21, 22]. Contrasting the biological effects of these two interventions aimed at the same organ system (muscle, blood, brain) is possible

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Conclusion