DC-magnetoencephalography and time-resolved near-infrared spectroscopy combined to study neuronal and vascular brain responses.
Physiol Meas
; 28(6): 651-64, 2007 Jun.
Article
in En
| MEDLINE
| ID: mdl-17664619
ABSTRACT
The temporal relation between vascular and neuronal responses of the brain to external stimuli is not precisely known. For a better understanding of the neuro-vascular coupling changes in cerebral blood volume and oxygenation have to be measured simultaneously with neuronal currents. With this motivation modulation dc-magnetoencephalography was combined with multi-channel time-resolved near-infrared spectroscopy to simultaneously monitor neuronal and vascular parameters on a scale of seconds. Here, the technique is described, how magnetic and optical signals can be measured simultaneously. In a simple motor activation paradigm (alternating 30 s of finger movement with 30 s of rest for 40 min) both signals were recorded non-invasively over the motor cortex of eight subjects. The off-line averaged signals from both modalities showed distinct stimulation related changes. By plotting changes in oxy- or deoxyhaemoglobin as a function of magnetic field a characteristic trajectory was created, which was similar to a hysteresis loop. A parametric analysis allowed quantitative results regarding the timing of coupling the vascular signal increased significantly slower than the neuronal signal.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain
/
Magnetoencephalography
/
Spectroscopy, Near-Infrared
/
Neurons
Limits:
Humans
Language:
En
Journal:
Physiol Meas
Journal subject:
BIOFISICA
/
ENGENHARIA BIOMEDICA
/
FISIOLOGIA
Year:
2007
Document type:
Article
Affiliation country:
Alemania