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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2007-3-22
pubmed:abstractText
Although expression of some genes is known to change during neuronal activity or plasticity, the overall relationship of gene expression changes to memory or memory disorders is not well understood. Here, we combined extensive statistical microarray analyses with behavioral testing to comprehensively identify genes and pathways associated with aging and cognitive dysfunction. Aged rats were separated into cognitively unimpaired (AU) or impaired (AI) groups based on their Morris water maze performance relative to young-adult (Y) animals. Hippocampal gene expression was assessed in Y, AU, and AI on the fifth (last) day of maze training (5T) or 21 d posttraining (21PT) and in nontrained animals (eight groups total, one array per animal; n = 78 arrays). ANOVA and linear contrasts identified genes that differed from Y generally with aging (differed in both AU and AI) or selectively, with cognitive status (differed only in AI or AU). Altered pathways/processes were identified by overrepresentation analyses of changed genes. With general aging, there was downregulation of axonal growth, cytoskeletal assembly/transport, signaling, and lipogenic/uptake pathways, concomitant with upregulation in immune/inflammatory, lysosomal, lipid/protein degradation, cholesterol transport, transforming growth factor, and cAMP signaling pathways, primarily independent of training condition. Selectively, in AI, there was downregulation at 5T of immediate-early gene, Wnt (wingless integration site), insulin, and G-protein signaling, lipogenesis, and glucose utilization pathways, whereas Notch2 (oligodendrocyte development) and myelination pathways were upregulated, particularly at 21PT. In AU, receptor/signal transduction genes were upregulated, perhaps as compensatory responses. Immunohistochemistry confirmed and extended selected microarray results. Together, the findings suggest a new model, in which deficient neuroenergetics leads to downregulated neuronal signaling and increased glial activation, resulting in aging-related cognitive dysfunction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3098-110
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Hippocampal expression analyses reveal selective association of immediate-early, neuroenergetic, and myelinogenic pathways with cognitive impairment in aged rats.
pubmed:affiliation
Department of Functional Neuroscience, Memory Pharmaceuticals Corporation, Montvale, New Jersey 07645, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural