Topographical distribution of estrogen receptor in the forebrain of the neonatally highly estrogenized female rat — an immunocytochemical study

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TOPOGRAPHICAL DISTRIBUTION OF ESTROGEN RECEPTOR IN THE FOREBRAIN OF THE NEONATALLY HIGHLY ESTROGENIZED FEMALE RAT - AN IMMUNOCYTOCHEMICAL STUDY SHINJI HAYASHI AND HIROAKI OKAMURA, Department of Anatomy and Embryology. Tokyo Metropolitan Institute for Neuroscience, Tokyo 183, Japan. By transfection of a Ecoli strain with a vector containing a full length sequence of cDNA encoding rat estrogen receptor (rER), which had been kindly given by Prof.M.Muramatsu of University of Tokyo, we obtained rER protein fused with /%galactosidase. We succeeded to produce an antiserum from a rabbit which binds the rER both in the brain and uterus specifically. Using this, topographical distribution of rER was examined in the brain. The immunopositive materials were clearly located in the cell nuclei of certain hypothalamic nuclei such as the preoptic suprachiasmatic nucleus, the medial preoptic nucleus, the bed nucleus of the stria terminalis, the arcuate nucleus and the ventrolateral part of the ventromedial hypothalamic nucleus in the rat which showed regular sexual cycles or had been ovariectomized. It was also detected in the amygdalar structures such as the medial, the basolateral and the amygdalo-hippocampal nuclei. Topographical distribution of the rER was also examined in the sterile female rat which had received a large amount of estrogen neonatally. The topographical distribution of the rER in the hypothalamus of these rats was essentially the same as the neonatally nontreated, intact females. Thus, decreased responsiveness of the hypothalamic function to estrogen in the sterile female rats seemed not due to the distribution of ER in the hypothalamus.

EFFECT

OF

1’7 fi-ESTRADIOL

ON MORPHOLOGICAL

CHANGES

OF

TH-IMMUNOREACTIVE

NEURON

IN RAT

HYPOTHALAMUS KAZUNARI --___ Medicine,

YURI ___-. AND

MITSUHIRO --.--

It has been this complex

shown

that

to prove rat

brain.

was

ovariectomized

with

the

other

purfused The

sections

were

and dendritic

the effect

fixative

length

estrogen

and and

E,

treated

60,um-thick

were

analyzed here

on morphological

group.

stained

weeks

and

frontal

by computer-based

whereas.

dendritic

Universit~~

length

changes

after

the

anti-TH

third

the treatment, of

both

polyclonal system

ventricle

of each cell was larger

group

these

groups

antibody.

the

rats

were

of Soolied Biology,

size

in OVX t.han E; treated

of

SakyouAu, Kyoto 666, Japan.

It has been well known that firing

activity of osy-tocin (OXT) neurons in the supraoptic nucleus In contrast to males, ue found out the is facilitated by application of OXTin male animals. To investigate the inhibitory response of the OXTneurons to OXTapplication in virgin female rats. Ke studied the effect of gonadal hormone on the response mechanisms underlying this sex difference, of

09T

neurons to

ovariectomized firing

activity

almost all

OIT

by using hypothalamic

(2 ueeks before)

virgin

rats

and one neuron showed no response.

OXTneurons obtained

from ovariectomized

Moreover, all of the OXTneurons of virgin uere facilitated circulating

slices

their

estrogen

firing

activities

of rats.

were tested.

rats

neurons obtained

from

Five of six neurons showed an increased

On the other hand, OXTsuppressed and estrogen-treated

which Yere pre-treated

by the application

can modulate the response

OIT

activity

(17P-estradiol) with tamoaifen

of OXT. These results

of OXTneurons in the suplaoptic

of

rats. (antiestrogen)

indicate

were

size

statistically.

neuronal

Kyoto Institute

in and

mede.

Neuronal

and estimated

and

and

study,

neurons

EFFECT OF ESTROGENON OXYTOCIN NEURONSIN THE SUPRAOPTIC NUCLEUSOF RATS TOSHIHIRO NAKASH1H.A.ANDTOSHIKAZII KIYOH.ARA, Department

Technology, Matsunasaki.

of

of the neuron

In the present

of dopaminergic

sections

image analysis

around

synthesis.

One was ovariectomized(OVS)

Four

bp using

in the nucleus

or protein

into two groups.

horizontal

distributed

receptor(ERI

for peptide

devided

rat.s were

neurozls

in both groups,

with

of 17P-estradiol(E21

Wistar

immunohistochemicall~-

TH-immrrnoreactive consistent

combines

Prefectural

602, Japan..

on the gene expression

we intend

Kyoto

D~E~~~~~_n~__~f_Ana~~rn~,

Kxoto

estrogen

has an effect

the female the

KAWATA,

Kawar~~~_~h_i_j~~~~~.~o,

that

nucleus to OXT.

were

group.