PMID- 22036680
OWN - NLM
STAT- MEDLINE
DCOM- 20120517
LR  - 20220129
IS  - 1095-9572 (Electronic)
IS  - 1053-8119 (Linking)
VI  - 59
IP  - 3
DP  - 2012 Feb 1
TI  - Paired pulse depression in the somatosensory cortex: associations between MEG and 
      BOLD fMRI.
PG  - 2722-32
LID - 10.1016/j.neuroimage.2011.10.037 [doi]
AB  - Interpretation of the blood oxygen level dependent (BOLD) response measured using 
      functional magnetic resonance imaging (fMRI) requires an understanding of the 
      underlying neuronal activity. Here we report on a study using both 
      magnetoencephalography (MEG) and BOLD fMRI, to measure the brain's functional 
      response to electrical stimulation of the median nerve in a paired pulse 
      paradigm. Interstimulus Intervals (ISIs) of 0.25, 0.5, 0.75, 1.0, 1.5 and 2.0 s 
      are used to investigate how the MEG detected neural response to a second pulse is 
      affected by that from a preceding pulse and if these MEG modulations are 
      reflected in the BOLD response. We focus on neural oscillatory activity in the 
      beta-band (13-30 Hz) and the P35m component of the signal averaged evoked response 
      in the sensorimotor cortex. A spatial separation of beta ERD and ERS following each 
      pulse is demonstrated suggesting that these two effects arise from separate 
      neural generators, with ERS exhibiting a closer spatial relationship with the 
      BOLD response. The spatial distribution and extent of BOLD activity were 
      unaffected by ISI, but modulations in peak amplitude and latency were observed. 
      Non-linearities in both induced oscillatory activity ERS and in the signal 
      averaged evoked response are found for ISIs of up to 2s when the signal averaged 
      evoked response has returned to baseline, with the P35m component displaying 
      paired pulse depression effects. The beta-band ERS magnitude was modulated by ISI, 
      however the ERD magnitude was not. These results support the assumption that BOLD 
      non-linearity arises not only from a non-linear vascular response to neural 
      activity but also a non-linear neural response to the stimulus with ISI up to 2 
      s.
CI  - Copyright (c) 2011 Elsevier Inc. All rights reserved.
FAU - Stevenson, C M
AU  - Stevenson CM
AD  - Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, 
      University of Nottingham, Nottingham, UK. claire@neuro.hut.fi
FAU - Wang, F
AU  - Wang F
FAU - Brookes, M J
AU  - Brookes MJ
FAU - Zumer, J M
AU  - Zumer JM
FAU - Francis, S T
AU  - Francis ST
FAU - Morris, P G
AU  - Morris PG
LA  - eng
GR  - G0901321/MRC_/Medical Research Council/United Kingdom
PT  - Journal Article
DEP - 20111020
PL  - United States
TA  - Neuroimage
JT  - NeuroImage
JID - 9215515
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Cortical Synchronization
MH  - Data Interpretation, Statistical
MH  - Electric Stimulation
MH  - Evoked Potentials, Somatosensory/physiology
MH  - Excitatory Postsynaptic Potentials/physiology
MH  - Humans
MH  - Magnetic Resonance Imaging/*methods
MH  - Magnetoencephalography/*methods
MH  - Median Nerve/physiology
MH  - Motor Cortex/physiology
MH  - Nonlinear Dynamics
MH  - Normal Distribution
MH  - Oxygen/*blood
MH  - Somatosensory Cortex/*physiology
EDAT- 2011/11/01 06:00
MHDA- 2012/05/18 06:00
CRDT- 2011/11/01 06:00
PHST- 2011/07/27 00:00 [received]
PHST- 2011/09/23 00:00 [revised]
PHST- 2011/10/13 00:00 [accepted]
PHST- 2011/11/01 06:00 [entrez]
PHST- 2011/11/01 06:00 [pubmed]
PHST- 2012/05/18 06:00 [medline]
AID - S1053-8119(11)01201-8 [pii]
AID - 10.1016/j.neuroimage.2011.10.037 [doi]
PST - ppublish
SO  - Neuroimage. 2012 Feb 1;59(3):2722-32. doi: 10.1016/j.neuroimage.2011.10.037. Epub 
      2011 Oct 20.