Linked Life Data

14668212

Source:http://linkedlifedata.com/resource/pubmed/id/14668212

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-3-22
pubmed:abstractText
Daily rhythms in the timing of the preovulatory surge and the display of reproductive behavior are reversed in diurnal and nocturnal rodents, but little is known about the neural mechanisms underlying these differences. We examined this issue by comparing a diurnal murid rodent, Arvicanthis niloticus (the grass rat), to a nocturnal one, Rattus norvegicus (the lab rat). In the first study, we established that sequential estradiol and progesterone treatment induces a proestrous-like rise in LH secretion and in the percentage of GnRH neurons that express Fos in grass rats, as is the case in lab rats. Next, we tested the hypothesis that differences in the timing of estrus-related events in diurnal and nocturnal species are caused by differences in rhythms in responsiveness to steroid hormones. We found rhythms in GnRH neuron activity, as indicated by Fos, that were 12 hours out of phase in grass rats and lab rats. These patterns persisted in both species when animals were housed in constant darkness for 5 days, suggesting that they are driven by an endogenous circadian mechanism. These results indicate that steroid-primed grass rats and lab rats are similar with respect to the temporal relationship among estrus-related events, but that the timing of these events relative to the light-dark cycle is dramatically different and that this difference is caused by endogenous circadian mechanisms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3363
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1049-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Circadian regulation of gonadotropin-releasing hormone neurons and the preovulatory surge in luteinizing hormone in the diurnal rodent, Arvicanthis niloticus, and in a nocturnal rodent, Rattus norvegicus.
pubmed:affiliation
Department of Zoology, Michigan State University, East Lansing 48824, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.