Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-12-3
pubmed:abstractText
All perfusion-based imaging modalities depend on the relationship between neuronal and vascular activity. However, the relationship between stimulus and response was never fully characterized. With the use of optical imaging (intrinsic signals and intravascular fluorescent dyes) during repetitive stimulation paradigms, we observed reduced responses with temporally close stimuli. Cortical evoked potentials, however, did not produce the same reduced responsiveness. We therefore termed these intervals of reduced responsiveness "refractory periods." During these refractory periods an ability to respond was retained, but at a near 60% reduction in the initial magnitude. Although increasing the initial stimulus duration lengthened the observed refractory periods, significantly novel or temporally spaced stimuli overcame them. We observed this phenomenon in both rodent and human subjects in somatosensory and auditory cortices. These results have significant implications for understanding the capacities, mechanisms, and distributions of neurovascular coupling and thereby possess relevance to all perfusion-dependent functional imaging techniques.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
80
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1522-32
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Refractory periods observed by intrinsic signal and fluorescent dye imaging.
pubmed:affiliation
Department of Neurology, University of California, Los Angeles School of Medicine 90095-1769, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.