Document Detail

Regional changes in cerebral haemodynamics as a result of a visual stimulus measured by near infrared spectroscopy.
MedLine Citation:
PMID:  8587877     Owner:  NLM     Status:  MEDLINE    
Near infrared spectroscopy (NIRS) is used to measure global changes in cerebral haemodynamics. We have adapted the technique to measure regional changes in response to a visual stimulus. Ten volunteers were exposed to a computer generated visual stimulus designed to activate a large area of the visual cortex, including V1, V2, V3, V4 and V5. The stimulus was on for 30 s and off for 30 s. Changes in the concentrations of oxyhaemoglobin ([HbO2]) and deoxyhaemoglobin ([Hb]) were measured using a commercial spectrometer (NIRO500), over the occipital cortex. The data were summed over ten cycles. As a control, the experiment was repeated over the frontal cortex. For each subject [HbO2] increased during stimulation, and decreased when the stimulus was off. The mean (+/- s.e.m.) change in [HbO2] was 0.54 +/0 0.14 micromol 1(-1). The change in total haemoglobin concentration, given by [HbO2] + [Hb] was 0.61 +/- 0.21 micromol 1(-1), equivalent to a rise in cerebral blood volume of 0.04 +/- 0.01 ml 100 g(-1) which is about 2% of the total cerebral blood volume. There was no significant change in [HbO2] over the frontal cortex, implying that the changes in blood volume originated in the occipital lobe. This demonstrates that NIRS provides a non-invasive method of measuring regional changes in cerebral haemodynamics as a result of visual stimulation.
J H Meek; C E Elwell; M J Khan; J Romaya; J S Wyatt; D T Delpy; S Zeki
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Proceedings. Biological sciences / The Royal Society     Volume:  261     ISSN:  0962-8452     ISO Abbreviation:  Proc. Biol. Sci.     Publication Date:  1995 Sep 
Date Detail:
Created Date:  1996-03-25     Completed Date:  1996-03-25     Revised Date:  2009-09-29    
Medline Journal Info:
Nlm Unique ID:  101245157     Medline TA:  Proc Biol Sci     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  351-6     Citation Subset:  IM    
Department of Paediatrics, University College London, U.K.
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MeSH Terms
Blood Volume
Cerebral Cortex / blood supply*,  physiology*
Cerebrovascular Circulation*
Frontal Lobe / blood supply,  physiology
Hemoglobins / metabolism*
Occipital Lobe / blood supply,  physiology
Oxyhemoglobins / metabolism*
Reference Values
Spectrophotometry, Infrared / methods*
Visual Cortex / blood supply,  physiology
Visual Perception*
Grant Support
//Wellcome Trust
Reg. No./Substance:
0/Hemoglobins; 0/Oxyhemoglobins; 9008-02-0/deoxyhemoglobin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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