Imaging human intra-cerebral connectivity by PET during TMS : NeuroReport (original) (raw)

Brain Imaging

Fox, Peter1,2,3,4,5,10; Ingham, Roger6; George, Mark S.7,8,9; Mayberg, Helen1,2,3,4; Ingham, Janis6; Roby, John1,2; Martin, Charles1,2; Jerabek, Paul1,2

1Research Imaging Center, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-6240

2Department of Radiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-6240

3Department of Medicine (Neurology), University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-6240

4Department of Psychiatry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-6240

5Department of Physiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-6240

6Department of Speech and Hearing Sciences, University of California, Santa Barbara, Medical University of South Carolina, Charleston, SC, USA

7Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA

8Department of Radiology, Medical University of South Carolina, Charleston, SC, USA

9Department of Neurology, Medical University of South Carolina, Charleston, SC, USA.

10Corresponding Author and Address: Peter Fox, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-6240

ACKNOWLEDGEMENTS: This study was supported by a grant from the Research Imaging Center.

Received 1 May 1997; accepted 3 June 1997

Abstract

NON-INVASIVE imaging of human inter-regional neural connectivity by positron emission tomography (PET) during transcranial magnetic stimulation (TMS) was performed. The hand area of primary motor cortex (M1) in the left cerebral hemisphere was stimulated with TMS while local and remote effects were recorded with PET. At the stimulated site, TMS increased blood flow (12–20%) in a highly focal manner, without an inhibitory surround. Remote covariances, an index of connectivity with M1, were also focal. Connectivity patterns established in non-human species were generally confirmed. Excitatory connectivity (positive covariance) was observed in ipsilateral primary and secondary somatosensory areas (S1 and S2), in ipsilateral ventral, lateral premotor cortex (M2) and in contralateral supplementary motor area (SMA). Inhibitory connectivity (negative covariance) was observed in contralateral M1.