Parieto-frontal connectivity tested with paired pulse TMS

Abstract

Event Abstract Back to Event Parieto-frontal connectivity tested with paired pulse TMS Giacomo Koch1, Diane Ruge2 and John Rothwell2* 1 IRCCS, Fondazione Santa Lucia, Italy 2 UCL Institute of Neurology, United Kingdom We have recently developed a method for exploring parieto-motor interactions using a double pulse TMS method in which a conditioning stimulus is given over the posterior parietal cortex (PPC) prior to a test pulse given through a different coil over the motor cortex. If the interval between the pulses is 4-6 or 15ms, then the amplitude of the muscle twitch evoked by the test pulse is facilitated. The effect is spatially specific within the PPC, depends on the intensity of the conditioning pulse and is modulated during the course of planning reaching movements with the opposite arm, becoming facilitated early during the reaction time for reaches to the opposite side of space. We speculate that it can be used to probe the excitability of PPC-motor connections. Recently we have explored the effects of manipulating the excitability of PPC by giving a session of repetitive TMS over the same stimulation site. If a form of rTMS that is known to reduce excitability of motor cortex for a period of 30 min (continuous theta burst stimulation) is given over either left or right PPC, then the excitability of the PPC-M1 connection is reduced on the same side. Interestingly there are also effects on the PPC-M1 connections in the contralateral hemisphere: reduced excitability of the left PPC is accompanied by increased PPC-M1 connectivity in the right hemisphere; in contrast, reduced excitability of right PPC is accompanied by reduced excitability of left PPC. I will show some of the behavioural effects of such interventions and speculate on the relation of the results to neglect in stroke. Keywords: Parieto-frontal Conference: 41st European Brain and Behaviour Society Meeting, Rhodes Island, Greece, 13 Sep - 18 Sep, 2009. Presentation Type: Oral Presentation Topic: Symposia lectures Citation: Koch G, Ruge D and Rothwell J (2009). Parieto-frontal connectivity tested with paired pulse TMS. Conference Abstract: 41st European Brain and Behaviour Society Meeting. doi: 10.3389/conf.neuro.08.2009.09.032 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 Jun 2009; Published Online: 04 Jun 2009. * Correspondence: Dr. John Rothwell, UCL Institute of Neurology, London, United Kingdom, j.rothwell@ion.ucl.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Giacomo Koch Diane Ruge John Rothwell Google Giacomo Koch Diane Ruge John Rothwell Google Scholar Giacomo Koch Diane Ruge John Rothwell PubMed Giacomo Koch Diane Ruge John Rothwell Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.