European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 5 - Number 3
Eur J Anat, 5 (3): 139-143 (2001)

Sexual dimorphism in rat oxytocinergic hypothalamic regions

Herbert Z., Sauer B., Jirikowski G.F.

Institut für Anatomie II, Friedrich-Schiller-Universitat Jena, Teichgraben 7, 07743 Jena, Germany

ABSTRACT Oxytocin (OT), a nonapeptide of the hypothalamo-neurohypophyseal system is known to be important for milk ejection and uterus contraction in females and for erection and seminal emissions in males. These sex-specific functional properties imply differential distribution of OT in the hypothalamus. In the present study, complete series of vibratome sections of male and female rat brains were stained for OT with either immunoperoxidase or immunofluorescence in order to evaluate such sex differences. While no significant differences were found in the classical magnocellular nuclei, females had more OT neurons in the zona incerta and the retrochiasmatic portion of the supraoptic nucleus. In males, the lateral subcommissural nucleus and the lateral preoptic area contained significantly more OT perikarya. These sexually dimorphic locations of OT-expressing neurons may be the neuroanatomical correlates of known gender-specific functions of OT.

Keywords: oxytocin, peroxidase, animal tissue, article, controlled study, female, hypothalamus, immunocytochemistry, immunofluorescence, male, nonhuman, preoptic area, rat, sex difference, subcommissural organ, supraoptic nucleus, zona incerta

European Journal of anatomy
ISSN 2340-311X (Online)