Transcranial magnetic stimulation (TMS), a non-invasive form of brain stimulation, produces lasting changes in the brain to treat depression and other brain disorders. Emphasis on clinical indications and efficacy has far outpaced a mechanistic understanding of how these changes are produced. In this study, we propose use of the pharmacologic agents d-cycloserine, demonstrated to be safe for human use, to probe in the molecular mechanism of long-term potentiation, the cellular basis of learning and memory. We will measure whether this agent can respectively strengthen the potentiation produced by TMS by looking at the amplitude of motor response (called motor evoked potential or MEP) of the thumb (through electromyography, or EMG).
A better understanding of its mechanism of action promises to optimize our ability to use TMS, and potentially improve duration and degree of response.