Construction and Evaluation of Rodent-Specific rTMS Coils. Academic Article uri icon

Overview

abstract

  • Rodent models of transcranial magnetic stimulation (TMS) play a crucial role in aiding the understanding of the cellular and molecular mechanisms underlying TMS induced plasticity. Rodent-specific TMS have previously been used to deliver focal stimulation at the cost of stimulus intensity (12 mT). Here we describe two novel TMS coils designed to deliver repetitive TMS (rTMS) at greater stimulation intensities whilst maintaining spatial resolution. Two circular coils (8 mm outer diameter) were constructed with either an air or pure iron-core. Peak magnetic field strength for the air and iron-cores were 90 and 120 mT, respectively, with the iron-core coil exhibiting less focality. Coil temperature and magnetic field stability for the two coils undergoing rTMS, were similar at 1 Hz but varied at 10 Hz. Finite element modeling of 10 Hz rTMS with the iron-core in a simplified rat brain model suggests a peak electric field of 85 and 12.7 V/m, within the skull and the brain, respectively. Delivering 10 Hz rTMS to the motor cortex of anaesthetized rats with the iron-core coil significantly increased motor evoked potential amplitudes immediately after stimulation (n = 4). Our results suggest these novel coils generate modest magnetic and electric fields, capable of altering cortical excitability and provide an alternative method to investigate the mechanisms underlying rTMS-induced plasticity in an experimental setting.

publication date

  • June 30, 2016

Research

keywords

  • Computer Simulation
  • Equipment Design
  • Evoked Potentials, Motor
  • Motor Cortex
  • Transcranial Magnetic Stimulation

Identity

PubMed Central ID

  • PMC4928644

Scopus Document Identifier

  • 84978747574

Digital Object Identifier (DOI)

  • 10.1016/0168-5597(92)90135-X

PubMed ID

  • 27445702

Additional Document Info

volume

  • 10