AVP and Anxiety: In addition to examining these adult behaviors, we evaluated the blood testosterone levels and the numbers of cells expressing arginine-vasopressin (AVP) in the hypothalamus because they are closely associated with socio-sexual and anxiety-related behaviors (Hull and Dominguez, 2007; Nelson and Trainor, 2007; Ho et al., 2010; Stevenson and Caldwell, 2012).