Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-3-11
pubmed:abstractText
Testosterone exerts important feedback effects on the hypothalamus of the ram to influence reproductive functioning. To provide a neuroanatomical basis for understanding this androgen action, the present study has examined androgen receptor (AR) immunoreactivity within the hypothalamus and adjacent brain areas of the intact non-breeding season ram. The largest populations of AR-immunoreactive cells were detected in the medial preoptic area, infundibular and premammillary nuclei in addition to the ventromedial nucleus (VMN) where cells were found distributed throughout its medial and lateral divisions. Smaller numbers of AR-expressing cells were identified in the bed nucleus of the stria terminalis and anterior hypothalamic area (AHA) including the paraventricular, but not the supraoptic, nucleus. Double-labelling immunocytochemistry revealed the presence of AR immunoreactivity in only 2 of 460 gonadotropin-releasing hormone (GnRH) neurons. A very small population of TH-immunoreactive cells located in the lateral aspect of the AHA was found to contain ARs. Dopaminergic cells elsewhere in the hypothalamus, including the infundibular nucleus, did not display AR immunoreactivity. Nearly 50% of AR-expressing cells in the lateral VMN were immunoreactive for somatostatin while less than 5% of periventricular somatostatin neurons displayed AR immunoreactivity. These results show where ARs are expressed in the ram hypothalamus and indicate the neuroanatomical sites at which androgen may act to influence reproductive function. The absence of ARs in the neuroendocrine GnRH and tuberoinfundibular dopaminergic cells suggests that androgens do not influence the genome of these cells in any direct manner. In contrast, the somatostatin neurons of the VMN appear to be an important target for circulating androgens in the non-breeding season ram.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0028-3835
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
120-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Androgen receptor-immunoreactive cells in ram hypothalamus: distribution and co-localization patterns with gonadotropin-releasing hormone, somatostatin and tyrosine hydroxylase.
pubmed:affiliation
Laboratory of Neuroendocrinology, The Babraham Institute, Cambridge, UK.
pubmed:publicationType
Journal Article