Decreased social interactions and an increase in self-directed activity have been observed following bilateral ablation of the entire amygdala in monkeys. Decreased social interactions has also been observed following the selective blockade of GABA-A receptors unilaterally in basolateral amygdala (BLA) (Malkova et al., 2003). Conversely, the activation of GABA-A receptors bilaterally in BLA caused a pronounced increase in affiliative social interactions, such as grooming (Lower et al., SFN Abst 2002). Here we investigated the effects of bilateral microinfusions of the NMDA antagonist, AP7 (20nmol), bilaterally into BLA on social interactions in four familiarized dyads of pigtailed macaques. Using a randomized design, one monkey at a time in each dyad received saline or drug treatment (with at least 3 replications); drug sessions alternated with baseline sessions and changes in behavior occurring during the 2hr following treatment were compared within animals across sessions. Significant (p<0.05) changes in...