Standardized Induction and Assessment of Long-term Potentiation-like Cortical Plasticity Using Transcranial Magnetic Stimulation

In recent years, transcranial magnetic stimulation (TMS) has emerged as a non-invasive, low-cost, and effective technique for assessing synaptic changes in the brain. Synaptic plasticity is a fundamental mechanism of neural plasticity that reflects the brain's ability to modify the strength and efficacy of synaptic connections in response to experience or environmental stimuli. Long-term potentiation (LTP) serves as the predominant experimental model for studying synaptic plasticity mechanisms, playing a critical role in understanding synaptic plasticity and overall brain function. Specific stimulation patterns, especially repetitive or burst patterns of pulses such as intermittent theta burst stimulation (iTBS), could induce LTP-like cortical plasticity, providing a feasible non-invasive approach to evaluate synaptic plasticity. However, the application of these techniques requires strict adherence to standardized protocols to ensure the accuracy and reliability of the results. Therefore, this article aims to demonstrate a standardized approach for inducing LTP-like plasticity using iTBS, followed by assessment of synaptic plasticity with single-pulse TMS, with both procedures guided by a neuronavigation system. The focus of this article will be on the essential technical procedures and operational considerations necessary to achieve precise and reliable measurements of cortical plasticity.