Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

The proposed project focuses on the evaluation of skeletal muscle, exercise, and brain-muscle interaction. In an unprecedented fashion brain and muscle will be evaluated with functional magnetic resonance imaging (fMRI, based on the blood-oxygen level dependent (BOLD) signal) methods prior to, during and after exercise. In addition, electromyography (EMG) and electroencephalography (EEG) will be done concurrent with MRI to record electrical activity in both tissues. Also, because the movement of sodium ions (Na+) in and out of cells is one of the driving forces of electrical activity in the tissues, intra and extracellular muscle (Na i Na e ) will be related in brain to EEG and in muscle to changing EMG activity. This highly innovative project is unique due to use of an in-bore MRI compatible Lode cycle ergometer, MRI compatible 64 channel EEG and 8 channel EMG systems. Furthermore, no research has ever been performed to concurrently assess human brain/muscle activity during exercise.
Long term Goals:
1) To understand how skeletal muscle BOLD and Na i Na e signals relate to muscle electrical activity, measured using EMG.
2) To determine how motion contributes to and can be corrected for in muscle BOLD signals.
3) To understand spatially and temporally localized changes in brain function (fMRI, EEG and Nai/Na e ) when activating skeletal muscle with differing kinds of exercise.
4) To temporally correlate brain activity from EEG, fMRI and Na i /Na e MRI with muscle EMG, BOLD and Na i Na e signals, and under various exercise paradigms.
5) To determine spatial and temporal correlations between brain and muscle activation during exercise, when comparing muscle extension and flexion, and isometric and isokinetic force.
Objectives:
1) Development of non-invasive MRI approaches to temporally assess physiology in vivo .
2) To enhanced the speed at which these measures can be performed
3) To develop novel methods that can corroborate MRI measures.
Summary of Scientific Approach:
BOLD MR imaging, and Na-MRI measures will be performed in brain and leg skeletal muscles before, during and following a range of exercise paradigms (isometric and isokinetic) with differing load/intensity, in healthy volunteers. Correlation and coherence analysis will be done to compare tissue BOLD and EMG activity. Muscle spatial activation will be compared to temporal changes in brain activation. Accelerated Na-MRI acquisition speed will be done using phased array RF coils and compressed sensing.