Linked Life Data

12723884

Source:http://linkedlifedata.com/resource/pubmed/id/12723884

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-5-1
pubmed:abstractText
Six Mongolian gerbils were studied for 8-10d while housed in separate cages in a 12:12h light-dark (L-D) cycle (lights on at 07:00h). Recordings of body temperature, heart rate, and spontaneous activity were made throughout. The temperature and heart rate rhythms were "purified" to take into account the effects of activity, and then the rhythm of temperature was further purified to take into account other masking influences ("non-activity masking effects" or NAME,). The methods employed in the purification processes involved linear regression analysis or analysis of covariance, the latter using functions of activity and NAME as covariates. From these methods, it was possible to obtain not only an estimate of the endogenous component of the temperature rhythm but also a measure of circadian changes in the sensitivity of temperature to masking effects. Even though all purification methods removed many of the effects of spontaneous activity from the temperature record, there remained temperature fluctuations at the L-D and D-L transitions that appeared to be independent of activity. The NAME was of only very marginal value in the purification process. Comparison of the purification methods indicated that the linear methods were inferior (both from a biological viewpoint and when the results were compared mathematically) to those that allowed the rate of rise of temperature due to increasing amounts of activity to become progressively less. The sensitivity of temperature and heart rate to the masking effects of activity showed a circadian rhythm, with sensitivities in the resting phase being greater than those in the active phase. These findings are compatible with the view that thermoregulatory reflexes are induced by spontaneous activity of sufficient amount, and that there is a circadian rhythm in the body temperature at which these reflexes are initiated and in their effectiveness.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0742-0528
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
249-70
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
The development of new purification methods to assess the circadian rhythm of body temperature in Mongolian gerbils.
pubmed:affiliation
Institute of Zoology, University of Halle, Halle, Germany. weinert@zoologie.uni-halle.de
pubmed:publicationType
Journal Article