Linked Life Data

17440492

Source:http://linkedlifedata.com/resource/pubmed/id/17440492

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2007-11-16
pubmed:abstractText
The contribution of glutamatergic and gamma-aminobutyric acid (GABA)ergic neurons to oxidative energy metabolism and neurotransmission in the developing brain is not known. Glutamatergic and GABAergic fluxes were assessed in neocortex of postnatal day 10 (P10) and 30 (P30) urethane-anesthetized rats infused intravenously with [1,6-(13)C(2)]glucose for different time intervals (time course) or with [2-(13)C]acetate for 2 to 3 h (steady state). Amino acid levels and (13)C enrichments were determined in tissue extracts ex vivo using (1)H-[(13)C]-NMR spectroscopy. Metabolic fluxes were estimated from the best fits of a three-compartment metabolic model (glutamatergic neurons, GABAergic neurons, and astroglia) to the (13)C-enrichment time courses of amino acids from [1,6-(13)C(2)]glucose, constrained by the ratios of neurotransmitter cycling (V(cyc))-to-tricarboxylic acid (TCA) cycle flux (V(TCAn)) calculated from the steady-state [2-(13)C]acetate enrichment data. From P10 to P30 increases in total neuronal (glutamate plus GABA) TCA cycle flux (3 x ; 0.24+/-0.05 versus 0.71+/-0.07 micromol per g per min, P<0.0001) and total neurotransmitter cycling flux (3.1 to 5 x ; 0.07 to 0.11 (+/-0.03) versus 0.34+/-0.03 micromol per g per min, P<0.0001) were approximately proportional. Incremental changes in total cycling (DeltaV(cyc(tot))) and neuronal TCA cycle flux (DeltaV(TCAn(tot))) between P10 and P30 were 0.23 to 0.27 and 0.47 micromol per g per min, respectively, similar to the approximately 1:2 relationship previously reported for adult cortex. For the individual neurons, increases in V(TCAn) and V(cyc) were similar in magnitude (glutamatergic neurons, 2.7 x versus 2.8 to 4.6 x ; GABAergic neurons, approximately 5 x versus approximately 7 x), although GABAergic flux changes were larger. The findings show that glutamate and GABA neurons undergo large and approximately proportional increases in neurotransmitter cycling and oxidative energy metabolism during this major postnatal growth spurt.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1895-907
pubmed:meshHeading
pubmed-meshheading:17440492-Acetates, pubmed-meshheading:17440492-Algorithms, pubmed-meshheading:17440492-Amino Acids, pubmed-meshheading:17440492-Animals, pubmed-meshheading:17440492-Blood Glucose, pubmed-meshheading:17440492-Brain Chemistry, pubmed-meshheading:17440492-Cerebral Cortex, pubmed-meshheading:17440492-Citric Acid Cycle, pubmed-meshheading:17440492-Data Interpretation, Statistical, pubmed-meshheading:17440492-Energy Metabolism, pubmed-meshheading:17440492-Glucose, pubmed-meshheading:17440492-Glutamic Acid, pubmed-meshheading:17440492-Kinetics, pubmed-meshheading:17440492-Magnetic Resonance Spectroscopy, pubmed-meshheading:17440492-Male, pubmed-meshheading:17440492-Neuroglia, pubmed-meshheading:17440492-Neurons, pubmed-meshheading:17440492-Neurotransmitter Agents, pubmed-meshheading:17440492-Rats, pubmed-meshheading:17440492-Rats, Sprague-Dawley, pubmed-meshheading:17440492-gamma-Aminobutyric Acid
pubmed:year
2007
pubmed:articleTitle
Glutamatergic and GABAergic neurotransmitter cycling and energy metabolism in rat cerebral cortex during postnatal development.
pubmed:affiliation
Department of Diagnostic Radiology, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut 06520, USA. golam.chowdhury@yale.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural