The purpose of this study is to examine the relationship between common clinical assessments and measurements of the function of brain-spinal cord-muscle connections. For examining brain-to-muscle pathways, we use a transcranial magnetic stimulator. This stimulator produces a magnetic field for a very short period of time and indirectly stimulates brain cells with little or no discomfort. We hope that the results of this training study will help us in developing therapy strategies for individuals, better understanding clinical assessments, and understanding treatments that aim to improve function recovery in people with SCI.

There are 2 aims for this study. The purpose of the first is to examine the relationship between assessments commonly used in therapy and doctor's offices (clinical assessments) and measurements of the function of brain-spinal cord- muscle connections. This will require 2 visits, and each visit will last approximately 2 hours.

The purpose of the second aim is to examine the effects of training on brain-spinal cord-muscle response. This will require 30 visits, and each visit will last approximately 1.5 hours.

Aerobic exercise training has positive effects on depression severity and mood in individuals with depression. The effects of single sessions of aerobic exercise may also provide some short-term benefits in depression. It is believed that a reduction in depression severity may be facilitated by changes in the nervous system, however this has yet to be examined. Although aerobic exercise has beneficial effects for those with depression it is unclear as to why this may occur. Therefore the goal of our project is to better understand the effect of a single session of aerobic exercise on the nervous system, physiology, and mood in depression.

Reflexes are important parts of our movements. When reflexes are not working well, movements are clumsy or even impossible. After stroke, reflex responses may change. Researchers have found that people can learn to increase or decrease a reflex response with training. Recently, we have found that rats and people with partial spinal cord injuries can walk better after they are trained to change a spinal cord reflex. Thus, learning to change a reflex response may help people recover after a nervous system injury. In this study, we aim to examine whether learning to change a spinal reflex through operant conditioning training can improve movement function recovery in people after stroke or other damage to the nervous system.

Reflexes are important parts of our movements. When reflexes are not working well, movements are clumsy or even impossible. Researchers have found that people can learn to increase or decrease a reflex response with training. Recently, we have found that rats with spinal cord injuries can walk better after they are trained to change a spinal cord reflex. Thus, learning to change a reflex response may help people recover after a nervous system injury. We are currently studying effects of spinal cord reflex training (e.g., a knee jerk reflex) in people in early adulthood. We hope that the results of this study will help us develop spinal reflex training as a new treatment to help people in early adulthood recover better after spinal cord injury or other damage to the nervous system.

Reflexes are important parts of our movements. When reflexes are not working well, movements are clumsy or even impossible. After spinal cord injury, reflex responses may change. Researchers have found that people can learn to increase or decrease a reflex response with training. Recently, we have found that rats with spinal cord injuries can walk better after they are trained to change a spinal reflex. Thus, learning to change a reflex response may help people recover after a nervous system injury. In this study, we aim to examine whether learning to change a spinal reflex through operant conditioning training can improve movement function recovery after spinal cord injury.