Membrane properties of the hypothalamic paraventricular nucleus neurons projecting to the spinal cord in the rat

S242 MEMBRANE

516

PROPERTIES

PROJECTING

KIYOTAKA

NOSE’,

Depts. ‘Physiol.

MIYAHARA’,

and *Neurosurg.,

membrane

immunohistochemical

studies

properties

extensively,

the properties

of

with antibodies

reported. Thus, we conducted

SINICHIRO

WAKISAKA’

Miyazaki Medical College, Kiyotake.

Electrophysiological

PVN neurons

PARAVENTRICULAR

paraventricular

directed

against

AND HIROSHI

parvocellular

nucleus

(PVN)

to neurophysin

of PVN neurons classified

low threshold

functionally

neurons

classified

based on the projecting properties

of fluorescent carbocyanine

based

have been

on

studied

sites have not been

of preautonomic

parvocelluIar

dye Dil was injected into the cervical

slices were made from pups.

The neurons

potential in the whole cell patch clamp method with current clamp mode. Because PVN

neurons have been reported to show low threshold

projecting to spinal cord has electrophysiological

517

KANNAN’

or related peptides

to examine in vitro characteristic electrophysiological

projecting to the spinal cord. A suspension

EFFECIS

NEURONS

Miyazaki, 889-1692

spinal cord in Wistar rat pups (3 days old ). Seven to I6 days later, hypothalamic labeled Dil showed

NUCLEUS

TO THE SPINAL CORD IN THE RAT.

SATOSHI

however,

OF THE HYPOTHALAMIC

OF ARGINlNE

potential (Dudek, 199 I), it is suggested

membrane property

VASOTOCIN

similar to that of the parvocellular

ON REPROWCTIVE

BEHAVIOR

that PVN neuron

neuron.

IN THE NEW,

CYNOPS

PYRRHQGASTER

TOYODA, F. I, YAMAMOI’O, K.‘, TANAKA, S. 3, OGAWA, Y.‘, KIKUYAMA, ‘Department of Physiology, Waseda UniveIsity,

Nara Medical University,

Nara 634-8521,

Tokyo 169-0051, Japan;3Department

S.*

Japan; ‘Department

of Biology,

of Biology, Faculty of Science, Shizuoka

School of Education,

Univeaity,

Shizuoka

422-

8529, Japan. In the breeding

season,

male red-bellied

Cynops pyrrhogmter,

newts,

through the water toward the female’s snout by vigorously front of the female and deposits induced the deposition

of spermatophores. from abdominal

(sodefrin)

the injection.

AVT enhanced

AVT induced spermatophore

The neurohypophyseal

gland, judging

both the incidence deposition

and frequency

in sexually developed

ER p MRNA EXPRESSION

‘CHITOSE ORIKASA,

‘HIROSHI

(AVI’)

peptide seems to induce the discharge of a female-attracting

of courtship

content in the abdominal gland after

behavior

intact males exhibiting

in androgen-primed no courtship

castrated newts.

behavior.

These results

events in the male newts.

IN THE DEVELOPING

HAYASHI,

a pheromone

this behavior, the male parades in

injection of arginine vasotocin

from the decrease of the pheromone

suggest that AVT is involved in a series of reproductive

518

vibrating their tails.

Following

In the sexually mature male newts,

spermatophores.

pheromone

attract their female partner by sending

*SHINJI HAYASHI,

RAT FOREBRAIN

‘YASUO SAKUMA

‘Dept. of Physiology, Nippon Medical School, Sendagi 1, Bunkyo, Tokyo I 13-8602 2Dept. of Anat./Embryol., Tokyo Metropol. Inst. Neurosci., 2-6 Musashidai, Fuchu, Tokyo 183-8526 Estrogen is known

to play crucial physiological

roles in the development

include the sexual differentiation

of the brain and a variety of the reproductive

the steroid receptor superfamily,

i.e. ligand-activated

transcription

and sequenced as a novel steroid receptor that is expressed

in situ hybridization

histochemistry.

functions.

of the nervous

system,

which

The estrogen receptor is a member of

factors. Recently, estrogen receptor p (ERP) has been cloned

in the rat prostate and ovary. ERa and ERP are expressed

degree of overlaps in the rat tissue. We here report distribution using non-isotopic

and differentiation

pattern of the ERP molecules in the developing

in a large

rat forebrain

Male and female rats were perfused on the postnatal days 7. 14, 21 or

35. ERP mRNA were detected by using a cocktail of two digoxigenin-labeled

cRNA probes, i.e. complementary

to 56-610 and

to 1809-2094 nt. We detected the ERP mRNA in the regions such as the lateral septum, the anteroventral periventricular

nucleus,

the supraoptic

and the

nucleus,

tuberomammillary

the paraventricular

nucleus. Sex differences

nccleus,

the anterior part of the ventromedial

in ERP mRNA expression

hypothalamic

was also analyzed in the developing

nucleus, rat brain.