Effect of Intermittent Hypoxia in Healthy Individuals

The use of acute intermittent hypoxia (AIH) has been examined in animal and human studies to gain an understanding of its effect on spinal excitability and synaptic strength. Subsequently, the investigators have learned that the use of AIH results in new protein formation and spinal plasticity. The use of acute intermittent hypoxia demonstrates a potential for therapeutic utilization in individuals with neurologic injuries. However, little is known about the effect of AIH in healthy individuals. This work is necessary to understand the mechanisms of AIH-induced plasticity. As such, this research study seeks to evaluate the impact of a single session AIH on upper extremity motor function in healthy individuals.

The use of acute intermittent hypoxia (AIH), has been demonstrated, through human and animal studies, to be an effective way of increasing spinal motor excitability and strengthening residual synaptic connectivity. AIH utilizes short duration (\<2 min) exposures to reduced oxygen levels (\~10% inspired oxygen), with alternating exposures to air with normal oxygen levels (\~21% inspired oxygen).

Previous publications demonstrate that AIH is a safe and effective intervention to modify motor function in individual with chronic incomplete spinal cord injuries. The use of AIH has been shown to influence the activation in musculature, within 60-120 minutes of administration. In addition, when coupling AIH with overground gait training, an increase in functional endurance, as evaluated through the 6 minute walk test, and gait speed, as evaluated through the 10 meter walk test, were demonstrated. In addition, the use of hypoxic training has been studied in healthy individuals and athletes; however, literature examining the effect of a single bout of AIH on performance is limited.

Although AIH has proven to be a promising treatment in enhancing spinal excitability and strengthening existing synaptic connections within individuals with chronic spinal cord injuries, further examination also needs to be made on the impact of AIH on motor function in healthy individuals.

Eligibility Criteria:
Inclusion Criteria:

* No history of neurologic injury or progressive neuromuscular disorder
* Individuals ages 18-70 years old
* Must be medically stable with no history of cardiovascular instability, congestive heart failure or stroke
* Not currently (\>2 weeks) on any medications related to spasticity
* No history of Sleep apnea
* Not a current smoker
* Able to comply with protocol/study requirements

Exclusion Criteria:

* Recent change in the use of narcotic, anti-inflammatory or pain medication
* unstable medical conditions or any other clinical observation that may affect the candidate's performance, health, safety or the ability to participate in the study determined by the treating therapist or coordinating staff
* Active participation in another movement research study or therapy program
* Anti-spasticity drug injection less than 3 months prior to beginning treatment
* Musculoskeletal pain that interferes with participation in study
* Women who are currently, may be, or planning on becoming pregnant
* for fMRI participation, participants will be excluded if they have:
* Metal fragments in eyes or face
* Implantation of any electronic devices such as (but not limited to) cardiac pacemakers, cardiac defibrillators, cochlea implants, or nerve stimulators
* Vascular surgery
* Claustrophobia
* Body piercing or tattoos