Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2001-5-24
pubmed:abstractText
Positron-emission tomography and functional MRS imaging signals can be analyzed to derive neurophysiological values of cerebral blood flow or volume and cerebral metabolic consumption rates of glucose (CMR(Glc)) or oxygen (CMR(O(2))). Under basal physiological conditions in the adult mammalian brain, glucose oxidation is nearly complete so that the oxygen-to-glucose index (OGI), given by the ratio of CMR(O(2))/CMR(Glc), is close to the stoichiometric value of 6. However, a survey of functional imaging data suggests that the OGI is activity dependent, moving further below the oxidative value of 6 as activity is increased. Brain lactate concentrations also increase with stimulation. These results had led to the concept that brain activation is supported by anaerobic glucose metabolism, which was inconsistent with basal glucose oxidation. These differences are resolved here by a proposed model of glucose energetics, in which a fraction of glucose is cycled through the cerebral glycogen pool, a fraction that increases with degree of brain activation. The "glycogen shunt," although energetically less efficient than glycolysis, is followed because of its ability to supply glial energy in milliseconds for rapid neurotransmitter clearance, as a consequence of which OGI is lowered and lactate is increased. The value of OGI observed is consistent with passive lactate efflux, driven by the observed lactate concentration, for the few experiments with complete data. Although the OGI changes during activation, the energies required per neurotransmitter release (neuronal) and clearance (glial) are constant over a wide range of brain activity.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-10077669, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-10393978, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-10461925, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-10583955, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-10826536, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-11136626, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-11209049, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-1438317, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-1618937, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-1631079, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-1968068, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-2062861, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-2565546, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-2858850, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-3121791, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-3260686, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-3485282, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-5025645, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-5707418, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-6361813, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-6754750, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-7611392, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-7798329, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-7938003, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-7968433, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-8793107, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9419373, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9427252, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9530118, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9688733, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9751778, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9778568, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9787780, http://linkedlifedata.com/resource/pubmed/commentcorrection/11344262-9988650
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6417-22
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Cerebral energetics and the glycogen shunt: neurochemical basis of functional imaging.
pubmed:affiliation
Department of Diagnostic Radiology, Yale University, New Haven, CT 06510, USA. robert.shulman@yale.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't