The Journal of Neuroscience, August 1, 2001, 21(15):5652-5659
Target-Dependent Sexual Differentiation of a Limbic-Hypothalamic
Neural Pathway
Maria A.
Ibanez1,
Guibao
Gu1, and
Richard B.
Simerly1, 2
1 Division of Neuroscience, Oregon Regional Primate
Research Center, Beaverton, Oregon 97006, and 2 Program in
Neuroscience, Oregon Health and Sciences University, Portland, Oregon
97201
Neural pathways between sexually dimorphic forebrain regions
develop under the influence of sex steroid hormones during the perinatal period, but how these hormones specify precise sex-specific patterns of connectivity is unknown. A heterochronic coculture system
was used to demonstrate that sex steroid hormones direct development of
a sexually dimorphic limbic-hypothalamic neural pathway through a
target-dependent mechanism. Explants of the principal nucleus of the
bed nuclei of the stria terminalis (BSTp) extend neurites toward
explants of the anteroventral periventricular nucleus (AVPV) derived
from male but not female rats. Coculture of BSTp explants from male
rats with AVPV explants derived from females treated in
vivo with testosterone for 9 d resulted in a high density
of neurites extending from the BSTp to the AVPV explant, as was the
case when the BSTp explants were derived from females and the AVPV
explants were derived from males or androgen-treated females. These
in vitro findings suggest that during the postnatal period testosterone induces a target-derived, diffusible chemotropic activity that results in a sexually dimorphic pattern of connectivity.
Key words:
sexual differentiation; axonal guidance; anteroventral
periventricular nucleus; bed nucleus of the stria terminalis; coculture; preoptic region
Copyright © 2001 Society for Neuroscience 0270-6474/01/21155652-08$05.00/0
Previous Article | Next Article
