Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation

J Vis Exp. 2020 Feb 23:(156). doi: 10.3791/60706.

Abstract

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has provided important insights into fundamental processes of the brain like cognition, learning, and motor control. However, this approach cannot provide causal evidence for the involvement of brain areas of interest. Transcranial magnetic stimulation (TMS) is a powerful, noninvasive tool for studying the human brain that can overcome this limitation by transiently modifying brain activity. Here, we highlight recent advances using a paired-pulse, dual-site TMS method with two coils that causally probes cortico-cortical interactions in the human motor system during different task contexts. Additionally, we describe a dual-site TMS protocol based on cortical paired associative stimulation (cPAS) that transiently enhances synaptic efficiency in two interconnected brain areas by applying repeated pairs of cortical stimuli with two coils. These methods can provide a better understanding of the mechanisms underlying cognitive-motor function as well as a new perspective on manipulating specific neural pathways in a targeted fashion to modulate brain circuits and improve behavior. This approach may prove to be an effective tool to develop more sophisticated models of brain-behavior relations and improve diagnosis and treatment of many neurological and psychiatric disorders.

Publication types

  • Research Support, Non-U.S. Gov't
  • Video-Audio Media

MeSH terms

  • Adult
  • Brain / physiology
  • Cognition
  • Humans
  • Motor Activity / physiology*
  • Neural Pathways / physiology*
  • Transcranial Magnetic Stimulation*