Effect of direct application of estrogen aimed at lateral septum or dorsal raphe nucleus on lordosis behavior

Regional and sexual differences in rats

Motoyasu Satou, Korehito Yamanouchi

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The role of estrogen in lordosis-inhibiting systems in the lateral septum or the dorsal raphe nucleus was investigated in female and male rats. Ovariectomized rats received implantation of 22-gauge guide cannulae to the bilateral or right side of the lateral septum (LS and rLS, respectively), the dorsal raphe nucleus (DRN) or bilateral cortex (CX). In castrated male rats, bilateral implantations of the cannulae to the LS were carried out (mLS). Three behavioral tests in total were performed at 2-week intervals. In the first test, all animals were subcutaneously injected with 1.5 μg/kg estradiol benzoate (EB). Forty-four hours after EB, 0.5 mg progesterone (P) was injected and a behavioral test was started 4 h after P. These hormonal regimes were used in all tests. In the second test, 2 h before EB injection, 27-gauge cannulae filled with estradiol (E2) were inserted into the DRN, LS or CX through the guide cannulae and were kept there for 4 h. In the third test, cholesterol was implanted instead of E2 into these areas. In the first test, most females showed low levels of lordosis quotient (LQ) and most males showed no lordosis. In the second test, mean LQs in the LS or rLS groups of females increased but not in the DRN and CX groups. In the mLS group no increase of LQ was observed. When cholesterol was implanted in the third test, mean LQs in all groups were as low as in the first test. These results suggest the possibility that estrogen releases the inhibition when it acts on the LS, but not on the DRN female rats. On the other hand, inhibition in the male LS may not be released by the direct action of estrogen.

Original languageEnglish
Pages (from-to)446-452
Number of pages7
JournalNeuroendocrinology
Volume69
Issue number6
DOIs
Publication statusPublished - 1999

Fingerprint

Lordosis
Sexual Behavior
Estrogens
Cholesterol
Progesterone
Estradiol
Dorsal Raphe Nucleus
Injections
Cannula
estradiol 3-benzoate

Keywords

  • Dorsal raphe nucleus
  • Gonadal steroids
  • Lordosis
  • Septum
  • Sex dimorphism

ASJC Scopus subject areas

  • Endocrinology
  • Neuroscience(all)

Cite this

Effect of direct application of estrogen aimed at lateral septum or dorsal raphe nucleus on lordosis behavior : Regional and sexual differences in rats. / Satou, Motoyasu; Yamanouchi, Korehito.

In: Neuroendocrinology, Vol. 69, No. 6, 1999, p. 446-452.

Research output: Contribution to journalArticle

@article{170d5fae558c4f319f82febb0a8f0989,
title = "Effect of direct application of estrogen aimed at lateral septum or dorsal raphe nucleus on lordosis behavior: Regional and sexual differences in rats",
abstract = "The role of estrogen in lordosis-inhibiting systems in the lateral septum or the dorsal raphe nucleus was investigated in female and male rats. Ovariectomized rats received implantation of 22-gauge guide cannulae to the bilateral or right side of the lateral septum (LS and rLS, respectively), the dorsal raphe nucleus (DRN) or bilateral cortex (CX). In castrated male rats, bilateral implantations of the cannulae to the LS were carried out (mLS). Three behavioral tests in total were performed at 2-week intervals. In the first test, all animals were subcutaneously injected with 1.5 μg/kg estradiol benzoate (EB). Forty-four hours after EB, 0.5 mg progesterone (P) was injected and a behavioral test was started 4 h after P. These hormonal regimes were used in all tests. In the second test, 2 h before EB injection, 27-gauge cannulae filled with estradiol (E2) were inserted into the DRN, LS or CX through the guide cannulae and were kept there for 4 h. In the third test, cholesterol was implanted instead of E2 into these areas. In the first test, most females showed low levels of lordosis quotient (LQ) and most males showed no lordosis. In the second test, mean LQs in the LS or rLS groups of females increased but not in the DRN and CX groups. In the mLS group no increase of LQ was observed. When cholesterol was implanted in the third test, mean LQs in all groups were as low as in the first test. These results suggest the possibility that estrogen releases the inhibition when it acts on the LS, but not on the DRN female rats. On the other hand, inhibition in the male LS may not be released by the direct action of estrogen.",
keywords = "Dorsal raphe nucleus, Gonadal steroids, Lordosis, Septum, Sex dimorphism",
author = "Motoyasu Satou and Korehito Yamanouchi",
year = "1999",
doi = "10.1159/000054448",
language = "English",
volume = "69",
pages = "446--452",
journal = "Neuroendocrinology",
issn = "0028-3835",
publisher = "S. Karger AG",
number = "6",

}

TY - JOUR

T1 - Effect of direct application of estrogen aimed at lateral septum or dorsal raphe nucleus on lordosis behavior

T2 - Regional and sexual differences in rats

AU - Satou, Motoyasu

AU - Yamanouchi, Korehito

PY - 1999

Y1 - 1999

N2 - The role of estrogen in lordosis-inhibiting systems in the lateral septum or the dorsal raphe nucleus was investigated in female and male rats. Ovariectomized rats received implantation of 22-gauge guide cannulae to the bilateral or right side of the lateral septum (LS and rLS, respectively), the dorsal raphe nucleus (DRN) or bilateral cortex (CX). In castrated male rats, bilateral implantations of the cannulae to the LS were carried out (mLS). Three behavioral tests in total were performed at 2-week intervals. In the first test, all animals were subcutaneously injected with 1.5 μg/kg estradiol benzoate (EB). Forty-four hours after EB, 0.5 mg progesterone (P) was injected and a behavioral test was started 4 h after P. These hormonal regimes were used in all tests. In the second test, 2 h before EB injection, 27-gauge cannulae filled with estradiol (E2) were inserted into the DRN, LS or CX through the guide cannulae and were kept there for 4 h. In the third test, cholesterol was implanted instead of E2 into these areas. In the first test, most females showed low levels of lordosis quotient (LQ) and most males showed no lordosis. In the second test, mean LQs in the LS or rLS groups of females increased but not in the DRN and CX groups. In the mLS group no increase of LQ was observed. When cholesterol was implanted in the third test, mean LQs in all groups were as low as in the first test. These results suggest the possibility that estrogen releases the inhibition when it acts on the LS, but not on the DRN female rats. On the other hand, inhibition in the male LS may not be released by the direct action of estrogen.

AB - The role of estrogen in lordosis-inhibiting systems in the lateral septum or the dorsal raphe nucleus was investigated in female and male rats. Ovariectomized rats received implantation of 22-gauge guide cannulae to the bilateral or right side of the lateral septum (LS and rLS, respectively), the dorsal raphe nucleus (DRN) or bilateral cortex (CX). In castrated male rats, bilateral implantations of the cannulae to the LS were carried out (mLS). Three behavioral tests in total were performed at 2-week intervals. In the first test, all animals were subcutaneously injected with 1.5 μg/kg estradiol benzoate (EB). Forty-four hours after EB, 0.5 mg progesterone (P) was injected and a behavioral test was started 4 h after P. These hormonal regimes were used in all tests. In the second test, 2 h before EB injection, 27-gauge cannulae filled with estradiol (E2) were inserted into the DRN, LS or CX through the guide cannulae and were kept there for 4 h. In the third test, cholesterol was implanted instead of E2 into these areas. In the first test, most females showed low levels of lordosis quotient (LQ) and most males showed no lordosis. In the second test, mean LQs in the LS or rLS groups of females increased but not in the DRN and CX groups. In the mLS group no increase of LQ was observed. When cholesterol was implanted in the third test, mean LQs in all groups were as low as in the first test. These results suggest the possibility that estrogen releases the inhibition when it acts on the LS, but not on the DRN female rats. On the other hand, inhibition in the male LS may not be released by the direct action of estrogen.

KW - Dorsal raphe nucleus

KW - Gonadal steroids

KW - Lordosis

KW - Septum

KW - Sex dimorphism

UR - http://www.scopus.com/inward/record.url?scp=0032986466&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032986466&partnerID=8YFLogxK

U2 - 10.1159/000054448

DO - 10.1159/000054448

M3 - Article

VL - 69

SP - 446

EP - 452

JO - Neuroendocrinology

JF - Neuroendocrinology

SN - 0028-3835

IS - 6

ER -