ESTROGEN-RECEPTOR FOUND IN THE FACIAL NUCLEUS OF THE NEWBORN RAT IS SUPPRESSED BY EXOGENOUS ESTROGEN - IMMUNO AND IN-SITU HYBRIDIZATION HISTOCHEMICAL-STUDIES
C. Orikasa et al., ESTROGEN-RECEPTOR FOUND IN THE FACIAL NUCLEUS OF THE NEWBORN RAT IS SUPPRESSED BY EXOGENOUS ESTROGEN - IMMUNO AND IN-SITU HYBRIDIZATION HISTOCHEMICAL-STUDIES, Developmental brain research, 82(1-2), 1994, pp. 9-17
Expression of the messenger RNA coding estrogen receptor (ER-mRNA) was
detected in the ventromedial subnucleus of the facial nucleus of the
newborn rat by in situ hybridization histochemistry (ISHH). The hybrid
ization signal in this subnucleus increased from 1 to 6 days of age, t
hen decreased at 11 days. By immunohistochemistry (IHC) using an antis
erum which detects estrogen receptor (ER) specifically, immunopositive
signals were also detected in the same subnucleus of the adjacent sec
tions. On the other hand, neither of these signals were encountered in
the same subnucleus of the adult rat. Thus, the present result extend
our previous work (Yokosuka and Hayashi, 1992) showing that the expre
ssion of the ER in the facial nucleus is transient. A sex difference i
n the expression of ER molecules was not apparent by ISHH and IHC. Mor
eover,,daily injections of estradiol from the day of birth suppressed
the expression of ER in the subnucleus at 6 and 11 days of age. Thus,
as has been detected in the mediobasal hypothalamus, ER-mRNA was revea
led to be down-regulated by estrogen.