Linked Life Data

11752897

Source:http://linkedlifedata.com/resource/pubmed/id/11752897

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-12-25
pubmed:abstractText
Thyrotropin-releasing hormone (TRH) is released from the median eminence upon neural stimulation such as cold or suckling exposure. Concomitant with the cold- or suckling-induced release of TRH is a rapid and transient increase in the expression of proTRH mRNA in the paraventricular nucleus (PVN) of the hypothalamus. We employed two strategies to determine whether TRH neurons responding to cold exposure are different from those responding to suckling. First, we attempted to identify a marker of cellular activation in TRH neurons of the PVN. Cold induced c-fos expression in about 25% of TRH neurons of the PVN, but no induction was observed by suckling. Moreover, we explored the expression of a variety of immediate early genes including NGFI-A, fra-1 and c-jun, or CREB phosphorylation but found none to be induced by suckling. The number of cells expressing high levels of proTRH mRNA was counted and compared to total expressing cells. An increased number of cells expressing high levels of proTRH mRNA was observed when both stimuli were applied to the same animal, suggesting that different cells respond separately to each stimulus. We therefore analyzed the distribution of responsive TRH neurons as defined by the cellular level of proTRH mRNA. The proTRH mRNA signal was analyzed within three rostrocaudal zones of the PVN and within six mediolateral columns. Results showed that in response to cold, all areas of the PVN of the lactating rat present increased proTRH mRNA levels, including the anterior zone where few hypophysiotropic TRHergic cells are believed to reside. The distribution of the proTRH mRNA expressing cells in response to cold was quite comparable in female and in male rats. In contrast, the response after suckling was confined to the middle and caudal zones. Our results provide evidence of a functional specialization of TRH cells in the PVN.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0028-3835
pubmed:author
pubmed:copyrightInfo
Copyright 2001 S. Karger AG, Basel
pubmed:issnType
Print
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
407-22
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Differential responses of thyrotropin-releasing hormone (TRH) neurons to cold exposure or suckling indicate functional heterogeneity of the TRH system in the paraventricular nucleus of the rat hypothalamus.
pubmed:affiliation
Departmento Genética y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca/Mor., México.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't