Association of cerebral networks in resting state with sexual preference of homosexual men: a study of regional homogeneity and functional connectivity

PLoS One. 2013;8(3):e59426. doi: 10.1371/journal.pone.0059426. Epub 2013 Mar 21.

Abstract

Recent imaging studies have shown that brain morphology and neural activity during sexual arousal differ between homosexual and heterosexual men. However, functional differences in neural networks at the resting state is unknown. The study is to characterize the association of homosexual preference with measures of regional homogeneity and functional connectivity in the resting state. Participants were 26 healthy homosexual men and 26 age-matched healthy heterosexual men in whom we collected echo planar magnetic resonance imaging data in the resting state. The sexual orientation was evaluated using the Kinsey Scale. We first assessed group differences in regional homogeneity and then, taking the identified differences as seed regions, we compared groups in measures of functional connectivity from those seeds. The behavioral significances of the differences in regional homogeneity and functional connectivity were assessed by examining their associations with Kinsey Scores. Homosexual participants showed significantly reduced regional homogeneity in the left inferior occipital gyrus, right middle occipital gyrus, right superior occipital gyrus, left cuneus, right precuneus, and increased regional homogeneity in rectal gyrus, bilateral midbrain, and left temporal lobe. Regional homogeneity correlated positively with Kinsey scores in the left inferior occipital gyrus. The homosexual group also showed reduced functional connectivity between left middle temporal gyrus, left supra-marginal gyrus, right cuneus and the seed region, i.e. left inferior occipital gyrus. Additionly, the connection between the left inferior occipital gyrus and right thalamus correlated positively with Kinsey scores. These differences in regional homogeneity and functional connectivity may contribute to a better understanding of the neural basis of male sexual orientation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basal Metabolism*
  • Brain / metabolism
  • Brain / physiology*
  • Echo-Planar Imaging
  • Homosexuality, Male / psychology*
  • Humans
  • Male
  • Nerve Net / metabolism
  • Nerve Net / physiology*
  • Sexual Behavior / physiology*
  • Sexual Behavior / psychology*
  • Young Adult

Grants and funding

This work was supported by a grant from the Ministry of Science and Technology of the People’s Republic of China (2010CB833905), www.nsfc.gov.cn; and the National Natural Science Foundation of China (81101013), www.most.gov.cn. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.