The Effects of Single-Pulse Transcranial Magnetic Stimulation on the Autonomic Nervous System in Healthy Adults

The overall purpose of this study is to investigate the effects of TMS on the ANS.
Specifically; the investigator aim to determine if single-pulse TMS of the primary motor
cortex in the dominant hemisphere in healthy, young adults will significantly affect 1) heart
rate and heart rate variability, 2) blood pressure and 3) baroreflex function.

The first purpose of this study is to measure alterations in sympathetic and parasympathetic
activation in response to TMS. To do this, we will measure HRV immediately after single-pulse
TMS. The second purpose is to investigate the changes in blood pressure in response to TMS
and to determine whether the baroreflex, a critical modulator of blood pressure, is inhibited
by TMS.

Aim 1: To determine if single-pulse TMS of the primary motor cortex will significantly alter
heart rate variability. We hypothesize that single-pulse TMS of the primary motor cortex will
elicit an acute decrease in heart rate and result in improved heart rate variability
indicated by a significantly decreased LF power and increased HF power.

Aim 2: To determine if single-pulse TMS of the primary motor cortex will significantly alter
blood pressure and baroreflex sensitivity (BRS). We hypothesize that single-pulse TMS of the
primary motor cortex will elicit an acute decrease in blood pressure by inhibiting the
baroreflex.

Inclusion Criteria:

- healthy volunteers between 18-65 years old

Exclusion Criteria:

- pregnant or breastfeeding women

- previous episodes of seizures or fainting

- any implanted metal in their head

- history of migraines

- history of psychiatric disorder (e.g. depression, anxiety, ADHD, bi-polar disorder)

- currently taking medications that may alter autonomic function (e.g. blood pressure
medication, depression medication)