Decreased social interactions have been observed following complete bilateral ablation of the amygdala. In pigtail macaque dyads, decreased social interactions have also been observed after the selective blockade of GABAA receptors by bicuculline methiodide (BMI) infused unilaterally in basolateral amygdala (BLA) (Malkova et al., 2003). Conversely, the activation of GABAA receptors by focal infusions of muscimol (MUS) bilaterally in BLA resulted in a significant increase in affiliative social interactions, including grooming (Lower et al., SFN 2002). Here we investigated the role of central nucleus of amygdala (CeN) in social behavior using the same manipulations previously employed in BLA. In a randomized design, one monkey at a time (n=5) in each dyad received BMI, MUS, or saline infusions; drug sessions alternated with baseline sessions and changes in behavior occurring during the 2hr following treatment were compared within animals across sessions. Bilateral BMI had no effect on social interactions, wh...