Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2004-7-22
pubmed:abstractText
Understanding how the hippocampus processes information critical for establishing spatial and declarative memories will benefit greatly from determining not only what kind of information the hippocampus registers, but also how this information is processed across the different hippocampal subfields. We addressed this question using a novel immediate-early gene-based brain-imaging method (Arc/H1a catFISH) that allows comparisons of neuronal ensembles activated by two experiences separated by approximately 30 min. Rats exposed to the same environment twice activated CA3 and CA1 ensembles with a similarly high degree of overlap. Changing the identity or configuration of local cues, or changing distal cues, activated CA3 and CA1 ensembles with reduced overlap. Yet, the overlap was greater in CA3 than in CA1. In contrast, rats exposed to two completely different environments activated CA3 and CA1 ensembles with low overlap, and this overlap was even lower in CA3 compared with CA1. Thus, CA3 has a discontinuous, whereas CA1 has a graded, population response to alterations of an environment. Additionally, as indicated by the percentage of active neurons, the context representation was more sparse in CA3 (approximately 18%) than in CA1 (approximately 35%). Finally, CA3 and CA1 activity levels were not correlated within a session, arguing against a simple coactivation of these regions. Instead, the within-rat ratio of CA3/CA1 cell activity was correlated across sessions, suggesting that the balance of CA3/CA1 activity is individual specific. Taken together, these findings suggest that CA3 and CA1 neuronal ensembles perform distinct, yet complementary, functions in the processing of spatial and contextual information.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6489-96
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Differences in hippocampal neuronal population responses to modifications of an environmental context: evidence for distinct, yet complementary, functions of CA3 and CA1 ensembles.
pubmed:affiliation
Arizona Research Laboratories, Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, Arizona 85724-5115, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.