Abstract
Testosterone reduces anxiety-like behaviors in rodents and increases exploration of anxiogenic parts of the environment. Effects of testosterone on innate defensive behaviors remain understudied. Here, we demonstrate that exogenous testosterone reduces aversion to cat odor in male mice. This is reflected as increased exploration of area containing cat urine when castrated male mice are supplied with exogenous testosterone. We also report that exogenous testosterone leads to DNA hypomethylation of arginine vasopressin (AVP) promoter in posterodorsal medial amygdala (MePD) and medial bed nucleus of stria terminalis (BNST). Our observations suggest that testosterone acting on AVP system within extended medial amygdala might regulate defensive behaviors in mice.
Highlights
Approach-avoidance conflict has been routinely used to model anxiety in laboratory tests
We report that exogenous testosterone leads to DNA hypomethylation of arginine vasopressin (AVP) promoter in posterodorsal medial amygdala (MePD) and medial bed nucleus of stria terminalis (BNST)
Our observations suggest that testosterone acting on AVP system within extended medial amygdala might regulate defensive behaviors in mice
Summary
Approach-avoidance conflict has been routinely used to model anxiety in laboratory tests. This includes elevated plus-maze where approach to a novel area and simultaneous avoidance of open spaces is used to create a test with remarkable construct validity. Testosterone induces anxiolysis in this test as manifested by greater time spent on the open arms in both male mice (Aikey et al, 2002) and male rats (Bitran et al, 1993; Frye and Seliga, 2001). Anxiolytic effect of testosterone can be observed in tests that do not use exploration to construct approach-avoidance continuum, e.g., defensive burying in rats (Fernández-Guasti and Martínez-Mota, 2005). Innate or unconditioned fear is often modeled in laboratory using tests that do not use approachavoidance conflict as a building block. Instead innate fear is often measured as uni-dimensional avoidance of a predator, or more often an olfactory cue of the predator (Wallace and Rosen, 2000; Dielenberg and McGregor, 2001; King et al, 2005)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call