Repetitive transcranial magnetic stimulation (rTMS) is a modality for probing and altering
brain function in humans non-invasively. The technology relies on the principles of
electromagnetic induction, whereby magnetic fields have an associated electrical field. By
intersecting two magnetic fields safely generated outside the head, one can induce a focal
electrical current where the magnetic fields intersect in the brain, and this can depolarize
cell membranes and impact brain activity.
A well investigated phenomenon in neuroscience is the principle of long term potentiation
(LTP), and its converse long term depression (LTD), referring to the ability of neurons to
increase or decrease their connection strength in an activity dependent manner. They do this
through modifications to their electrochemical junctions, the synapses. We have previously
used the motor system as a model system to study the impact D-Cycloserine, an NMDA receptor
partial agonist, on synaptic plasticity after TMS.
Conventional therapeutic TMS is delivered once daily, however it is increasingly being
delivered multiple times per day in an effort to speed treatment effects. It is unclear how
adjunctive agents would impact these repeated stimulation designs.
Research Question:
Does the N-methyl-D-aspartate receptor partial agonist D-Cycloserine stabilize motor
plasticity across multiple daily sessions of TMS?