Reactivation of hippocampal cell assemblies: Effects of behavioral state, experience and EEG dynamics

Persistent Link:
http://hdl.handle.net/10150/284692
Title:
Reactivation of hippocampal cell assemblies: Effects of behavioral state, experience and EEG dynamics
Author:
Kudrimoti, Hemant Shashikant
Issue Date:
1999
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
During slow-wave sleep (SWS), traces of neuronal activity patterns from preceding behavior can be observed in rat hippocampus and neocortex. The spontaneous reactivation of these patterns is manifested as the reinstatement of the distribution of pairwise firing rate correlations within a population of simultaneously recorded neurons. The effects of behavioral state (quiet wakefulness, SWS and REM), interactions between two successive spatial experiences, and global modulation during 200 Hz EEG "ripples" on pattern reinstatement were studied in CA1 pyramidal cell population recordings. Pairwise firing rate correlations during often repeated experiences accounted for a significant proportion of the variance in these interactions in subsequent SWS or quiet wakefulness and, to a lesser degree, during SWS prior to the experience on a given day. The latter effect was absent for novel experiences, suggesting that a persistent memory trace develops with experience. Pattern reinstatement was strongest during sharp wave-ripple oscillations, suggesting that these events may reflect system convergence onto attractor states corresponding to previous experiences. When two different experiences occurred in succession, the statistically independent effects of both were evident in subsequent SWS. Thus, the patterns of neural activity reemerge spontaneously, and in an interleaved fashion, and do not necessarily reflect persistence of an active memory (i.e., reverberation). Firing rate correlations during REM sleep were not related to the preceding familiar experience, possibly as a consequence of trace decay during the intervening SWS. REM episodes also did not detectably influence the correlation structure in subsequent SWS, suggesting a lack of strengthening of memory traces during REM sleep, at least in the case of familiar experiences.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Biology, Neuroscience.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Neurosciences
Degree Grantor:
University of Arizona
Advisor:
McNaughton, B. L.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleReactivation of hippocampal cell assemblies: Effects of behavioral state, experience and EEG dynamicsen_US
dc.creatorKudrimoti, Hemant Shashikanten_US
dc.contributor.authorKudrimoti, Hemant Shashikanten_US
dc.date.issued1999en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractDuring slow-wave sleep (SWS), traces of neuronal activity patterns from preceding behavior can be observed in rat hippocampus and neocortex. The spontaneous reactivation of these patterns is manifested as the reinstatement of the distribution of pairwise firing rate correlations within a population of simultaneously recorded neurons. The effects of behavioral state (quiet wakefulness, SWS and REM), interactions between two successive spatial experiences, and global modulation during 200 Hz EEG "ripples" on pattern reinstatement were studied in CA1 pyramidal cell population recordings. Pairwise firing rate correlations during often repeated experiences accounted for a significant proportion of the variance in these interactions in subsequent SWS or quiet wakefulness and, to a lesser degree, during SWS prior to the experience on a given day. The latter effect was absent for novel experiences, suggesting that a persistent memory trace develops with experience. Pattern reinstatement was strongest during sharp wave-ripple oscillations, suggesting that these events may reflect system convergence onto attractor states corresponding to previous experiences. When two different experiences occurred in succession, the statistically independent effects of both were evident in subsequent SWS. Thus, the patterns of neural activity reemerge spontaneously, and in an interleaved fashion, and do not necessarily reflect persistence of an active memory (i.e., reverberation). Firing rate correlations during REM sleep were not related to the preceding familiar experience, possibly as a consequence of trace decay during the intervening SWS. REM episodes also did not detectably influence the correlation structure in subsequent SWS, suggesting a lack of strengthening of memory traces during REM sleep, at least in the case of familiar experiences.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectBiology, Neuroscience.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineNeurosciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMcNaughton, B. L.en_US
dc.identifier.proquest9946774en_US
dc.identifier.bibrecord.b39888204en_US
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