Abstract:
:Systematic treatment of hamsters with triazolam (TRZ) or novel wheel (NW) access will yield PRCs similar to those for neuropeptide Y. Both TRZ and NW access require an intact intergeniculate leaflet (IGL) to modulate circadian rhythm phase. It is commonly suggested that both stimulus types influence rhythm phase response via a mechanism associated with drug-induced or wheel access-associated locomotion. Furthermore, there have been suggestions that one or both of these stimulus conditions require an intact serotonergic system for modulation of rhythm phase. The present study investigated these issues by making serotonin neuron-specific neurotoxic lesions of the median or dorsal raphe nuclei and evaluating phase response of the hamster circadian locomotor rhythm to TRZ treatment or NW access. The expected effect of TRZ injected at CT 6 h on the average phase advance was virtually eliminated by destruction of serotonin neurons in the median, but not the dorsal, raphe nucleus. No control or lesioned animal engaged in substantial wheel running in response to TRZ. By contrast, all median raphe-lesioned hamsters that engaged in substantial amounts of running when given access to a NW had phase shifts comparable to control or dorsal raphe-lesioned animals. The results demonstrate that serotonergic neurons in the median raphe nucleus contribute to the regulation of rhythm phase response to TRZ and that it is unlikely that these neurons are necessary for phase response to NW access. The data further suggest the presence of separate pathways mediating phase response to the two stimulus conditions. These pathways converge on the IGL, a nucleus afferent to the circadian clock, that is necessary for the expression of phase response to each stimulus type.
journal_name
J Biol Rhythmsjournal_title
Journal of biological rhythmsauthors
Meyer-Bernstein EL,Morin LPdoi
10.1177/074873098129000327subject
Has Abstractpub_date
1998-12-01 00:00:00pages
494-505issue
6eissn
0748-7304issn
1552-4531journal_volume
13pub_type
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journal_title:Journal of biological rhythms
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doi:10.1177/0748730405283418
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
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journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/074873049300800304
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journal_title:Journal of biological rhythms
pub_type: 杂志文章
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更新日期:1992-04-01 00:00:00
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journal_title:Journal of biological rhythms
pub_type: 杂志文章,评审
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更新日期:2009-10-01 00:00:00
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journal_title:Journal of biological rhythms
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更新日期:1990-01-01 00:00:00
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更新日期:2018-06-01 00:00:00