Sexual partner preference, hypothalamic morphology and aromatase in rams

Charles Roselli, Kay Larkin, Jessica M. Schrunk, Fredrick Stormshak

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The male-oriented ram is a unique and valuable animal model for the study of hormonal, developmental and genetic contributions to sexual partner preference. Unlike most other mammalian models that are in use currently, variations in sexual attraction occur spontaneously in domestic ram populations. It is estimated that as many as 8â€"10% of rams exhibit a sexual partner preference for other males, classifying them as male-oriented rams. Studies have failed to identify any compelling social factors that can predict or explain the variations in sexual partner preferences of rams. Nor is there consensus on the endocrine and sensory responsiveness of male-oriented rams to other rams. However, a number of studies have reported differences in brain structure and function between male-oriented and female-oriented rams, suggesting that sexual partner preferences are neurologically hard-wired. Recently, we identified a sexually dimorphic nucleus (oSDN) in the sheep preoptic areaâ€"anterior hypothalamus. The oSDN is larger in female-oriented rams than in male-oriented rams and similar in size in male-oriented rams and ewes. In addition, mRNA levels for aromatase in the oSDN were higher in males than in females and were higher in female-oriented rams than in male-oriented rams. These results suggest a relationship between steroid hormones, specifically estrogens and oSDN morphology. In this review, we provide an overview of sexual behavior in rams and discuss the multiple factors that may contribute to the development and adult expression of same-sex partner preferences in rams.

Original languageEnglish (US)
Pages (from-to)233-245
Number of pages13
JournalPhysiology and Behavior
Volume83
Issue number2
DOIs
StatePublished - Nov 15 2004

Fingerprint

Aromatase
Sexual Partners
Anterior Hypothalamus
Preoptic Area
Sexual Behavior
Sheep
Consensus
Estrogens
Animal Models
Steroids
Hormones
Messenger RNA
Brain

Keywords

  • Aromatase
  • Preoptic area
  • Sexual dimorphism
  • Sexual partner preference

ASJC Scopus subject areas

  • Behavioral Neuroscience
  • Physiology (medical)

Cite this

Sexual partner preference, hypothalamic morphology and aromatase in rams. / Roselli, Charles; Larkin, Kay; Schrunk, Jessica M.; Stormshak, Fredrick.

In: Physiology and Behavior, Vol. 83, No. 2, 15.11.2004, p. 233-245.

Research output: Contribution to journalArticle

Roselli, Charles ; Larkin, Kay ; Schrunk, Jessica M. ; Stormshak, Fredrick. / Sexual partner preference, hypothalamic morphology and aromatase in rams. In: Physiology and Behavior. 2004 ; Vol. 83, No. 2. pp. 233-245.
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