Ruth I. Wood

Professor and Chair of Cell and Neurobiology

Ruth I. Wood

Research Topics

  • Sex: androgen control of male sexual behavior, sex differences in brain & behavior
  • Drugs: anabolic-androgenic steroid abuse; ethanol and social behavior
  • Cooperation: behavioral endocrinology of cooperative behavior

Research Images

Hamster sexual behavior: the male (right) approaches the female, investigates her anogenital region, and begins to copulate.Bidirectional tract tracing in the bed nucleus of the stria terminalis (BST) shows neurons projecting to BST adjacent to efferent fibers from BST.We are creating an atlas of the sheep for research and teaching purposes.Schematic of a sagittal section through the hamster head to illustrate pathways for mating behavior.

Research Overview

My research investigates neural circuits for behavior, including social behavior, addiction and mood. In particular, we are interested in how gonadal steroid hormones act in the brain, both during development and in the adult, to effect sex differences and modify behavior.

One line of research investigates the neurobiology of anabolic-androgenic steroid (AAS) abuse. AAS are drugs of abuse, but the potential for dependence and addiction remains unclear. Studies from our laboratory have shown that male and female rodents will voluntarily self-administer testosterone and other AAS. This suggests that AAS are potentially addictive, independent of their effects on muscle mass or athletic performance. We are currently exploring how AAS alter decision-making and response to risk.

We are also interested in the behavioral endocrinology of cooperation: how hormones modulate cooperative behavior. We have developed operant models to test cooperation in rats working for food reward. Our studies investigate the effects of oxytocin and prolactin to promote cooperation, and the effects of AAS to inhibit cooperative behavior.

Contact Information

Mailing Address Keck School of Medicine of USC
Department of Cell and Neurobiology
1333 San Pablo St., BMT 401
Los Angeles, CA 90033
Office Location BMT 401b
Office Phone (323) 442-1980
Lab Location BMT 408
Lab Phone (323) 442-2094
Fax (323) 442-2411
Office Location BMT 401b


  • BS 1986 Animal Science- University of California, Davis
  • PhD 1991 Physiology- University of Michigan
  • Post-doc 1991-1994 Anatomy & Cell Biology- University of Michigan

Selected Publications

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  • Wallin-Miller K, Li G, Kelishani D, Wood RI.  Anabolic-androgenic steroids decrease dendritic spine density in the nucleus accumbens of male rats.  Neuroscience. 2016 Aug 25;330:72-8. PubMed
  • Wood RI, Kim JY, Li GR. Cooperation in rats playing the iterated Prisoner's Dilemma game. Anim Behav. 2016 Apr 1;114:27-35. PubMed
  • Wood RI, Knoll AT, Levitt P. Social housing conditions and oxytocin and vasopressin receptors contribute to ethanol conditioned social preference in female mice. Physiol Behav. 2015 Nov 1;151:469-77. PubMed
  • Wallin KG, Alves JM, Wood RI. Anabolic-androgenic steroids and decision making: Probability and effort discounting in male rats. Psychoneuroendocrinology. 2015 Jul;57:84-92. PubMed
  • Wallin KG, Wood RI. Anabolic-androgenic steroids impair set-shifting and reversal learning in male rats. Eur Neuropsychopharmacol. 2015 Apr;25(4):583-90. PubMed
  • Kim JY, Wood RI. Anabolic-androgenic steroids and appetitive sexual behavior in male rats. Horm Behav. 2014 Sep;66(4):585-90. PubMed
  • Cooper SE, Wood RI. Androgens and opiates: testosterone interaction with morphine self-administration in male rats. Neuroreport. 2014 May 7;25(7):521-6. PubMed
  • Cooper SE, Goings SP, Kim JY, Wood RI. Testosterone enhances risk tolerance without altering motor impulsivity in male rats. Psychoneuroendocrinology. 2014 Feb;40:201-12. PubMed
  • Kent K, Butler K, Wood RI. Ethanol induces conditioned social preference in male mice. Alcohol Clin Exp Res. 2014 Apr;38(4):1184-92. PubMed
  • Pope HG Jr, Wood RI, Rogol A, Nyberg F, Bowers L, Bhasin S. Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement. Endocr Rev. 2014 Jun;35(3):341-75. PubMed