Neonatal 5HT activity antagonizes the masculinizing effect of testosterone on the luteinizing hormone release response to gonadal steroids and on brain structures in rats

Neonatal 5HT activity antagonizes the masculinizing effect of testosterone on the luteinizing... Hypothalamic 5HT concentrations are transiently lower in male compared to female Wistar rats in the second week post partum (pp) and our previous findings have shown that pharmacologically potentiating 5HT activity over this period feminizes certain aspects of sexually differentiated behaviours in adult males and androgenized females. In order to investigate whether neonatal testosterone and 5HT interact to influence physiological and morphological brain sexual differences, females, androgenized females and males were treated with the 5HT2 agonist (−) (2,5 dimethoxy‐4‐iodophenyl)‐2‐amino propane HCl ((−) DOI), over days 8–16 pp. In androgenized females (250 µg testosterone proprionate, day 2 pp) (−) DOI prevented the delay in vaginal opening, but did not prevent the androgen‐induced constant oestrus in females treated with 100 µg TP, day 2 pp. (−) DOI overcame the neonatal androgen effect in suppressing the positive feedback of ovarian steroids in a few males and androgenized females. (−) DOI had a feminizing effect on the volume of the anteroventral periventricular nucleus (normally smaller in males), by significantly increasing its volume in male and androgenized females. It also had a significant antagonistic effect on the testosterone‐induced increase in the volume of the sexually dimorphic nucleus of the preoptic area in males and androgenized females. These findings support the view that raised 5HT activity in the second week of life antagonizes the masculinizing effect of neonatal testosterone. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png European Journal of Neuroscience Wiley

Neonatal 5HT activity antagonizes the masculinizing effect of testosterone on the luteinizing hormone release response to gonadal steroids and on brain structures in rats

Loading next page...
 
/lp/wiley/neonatal-5ht-activity-antagonizes-the-masculinizing-effect-of-G5SVYnZGw0
Publisher
Wiley Subscription Services, Inc., A Wiley Company
Copyright
Copyright © 2004 Wiley Subscription Services, Inc., A Wiley Company
ISSN
0953-816X
eISSN
1460-9568
D.O.I.
10.1111/j.0953-816X.2003.03158.x
Publisher site
See Article on Publisher Site

Abstract

Hypothalamic 5HT concentrations are transiently lower in male compared to female Wistar rats in the second week post partum (pp) and our previous findings have shown that pharmacologically potentiating 5HT activity over this period feminizes certain aspects of sexually differentiated behaviours in adult males and androgenized females. In order to investigate whether neonatal testosterone and 5HT interact to influence physiological and morphological brain sexual differences, females, androgenized females and males were treated with the 5HT2 agonist (−) (2,5 dimethoxy‐4‐iodophenyl)‐2‐amino propane HCl ((−) DOI), over days 8–16 pp. In androgenized females (250 µg testosterone proprionate, day 2 pp) (−) DOI prevented the delay in vaginal opening, but did not prevent the androgen‐induced constant oestrus in females treated with 100 µg TP, day 2 pp. (−) DOI overcame the neonatal androgen effect in suppressing the positive feedback of ovarian steroids in a few males and androgenized females. (−) DOI had a feminizing effect on the volume of the anteroventral periventricular nucleus (normally smaller in males), by significantly increasing its volume in male and androgenized females. It also had a significant antagonistic effect on the testosterone‐induced increase in the volume of the sexually dimorphic nucleus of the preoptic area in males and androgenized females. These findings support the view that raised 5HT activity in the second week of life antagonizes the masculinizing effect of neonatal testosterone.

Journal

European Journal of NeuroscienceWiley

Published: Jan 1, 2004

References

  • Gonadal steroid induction of structural sex differences in the central nervous system
    Arnold, Arnold; Gorski, Gorski
  • Sex differences in neurotransmitter systems
    De Vries, De Vries
  • Lesions of the serotonergic system impair the facilitation of but not the tolerance to the effects of chronic clenbuterol administration
    Frances, Frances; Raisman, Raisman; Simon, Simon; Struck, Struck
  • Ontogeny of sex differences in the mammalian hypothalamus and preoptic area
    Tobet, Tobet; Hanni, Hanni

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off