The autonomic (self-regulating) nervous system is important for the function of many organs in the body. The vagus nerve is part of the autonomic nervous system. The vagus nerve carries incoming information from the nervous system to the brain, providing information about what the body is doing, and it also transmits outgoing information which governs a range of reflex responses. It plays an important role in the immune system. A part of the vagus nerve is reachable for stimulation at specific locations in the ear.

The purpose of this study is to better understand how different ways of stimulating the vagus nerve at the ear can affect a chemical marker of inflammation found in human blood that is associated with a variety of inflammatory diseases such as rheumatoid arthritis and lupus. This information may lead to in future studies to see if stimulation of the vagus nerve can improve inflammation in chronic inflammatory diseases.

Inclusion Criteria:

• Between 18 and 60 years old
• Currently healthy with no medical problems
• Non-smoker

Exclusion Criteria:

• History of any of the following: cardiac arrhythmia, coronary artery disease, chronic inflammatory disease, anemia, malignancy, depression, connective tissue disease (arthritis, vasculitis), neurologic disease, diabetes mellitus, renal disease, malignancy, dementia, psychiatric illness including active psychosis, or any other chronic medical condition
• Use of cholinergic, anti-cholinergic, or beta-blocking medications
• Family history of inflammatory disease
• Pregnancy
• Smoking
• Ear infection (otitis media or externa)
• Implanted vagus nerve stimulator