Citation

Goetz SM, Tang L, Thomason ME, Diamond MP, Hariri AR, Carré JM. Biol. Psychiatry 2014; 76(4): 324-331.

Affiliation

Department of Psychology (SMMG, LT, JMC); Department of Psychology (JMC), Nipissing University, North Bay, Ontario, Canada. Electronic address: justinca@nipissingu.ca.

Copyright

(Copyright © 2014, Elsevier Publishing)

DOI

10.1016/j.biopsych.2014.01.016

PMID

24576686

Abstract

BACKGROUND: Previous research suggests that testosterone (T) plays a key role in shaping competitive and aggressive behavior in humans, possibly by modulating threat-related neural circuitry. However, this research has been limited by the use of T augmentation that fails to account for baseline differences and has been conducted exclusively in women. Thus, the extent to which normal physiologic concentrations of T affect threat-related brain function in men remains unknown. METHODS: In the current study, we use a novel two-step pharmacologic challenge protocol to overcome these limitations and to evaluate causal modulation of threat- and aggression-related neural circuits by T in healthy young men (n = 16). First, we controlled for baseline differences in T through administration of a gonadotropin releasing hormone antagonist. Once a common baseline was established across participants, we then administered T to within the normal physiologic range. During this second step of the protocol we acquired functional neuroimaging data to examine the impact of T augmentation on neural circuitry supporting threat and aggression. RESULTS: Gonadotropin releasing hormone antagonism successfully reduced circulating concentrations of T and brought subjects to a common baseline. Administration of T rapidly increased circulating T concentrations and was associated with heightened reactivity of the amygdala, hypothalamus, and periaqueductal grey to angry facial expressions. CONCLUSIONS: These findings provide novel causal evidence that T rapidly potentiates the response of neural circuits mediating threat processing and aggressive behavior in men.

Language: en