Intranasal oxytocin in rhesus monkeys alters brain networks that detect social salience and reward.

In primates, resting state functional neuroimaging (rsfcMRI) has identified several large-scale, intrinsic brain networks, including the salience network (SN), which is involved in detecting stimulus salience. Intranasal oxytocin (IN-OT) has been shown to modulate the salience and rewarding quality of social stimuli in mammals and numerous studies have shown that it can affect the functional connectivity between brain regions. Less is known, however, about how these effects unfold over time following IN-OT administration. This study used rsfcMRI in anesthetized rhesus macaques to track temporal changes in the functional connectivity between brain regions involved in the SN, including the anterior cingulate cortex (ACC), anterior insula (AI), amygdala (amy), and ventral striatum (vstr), lasting 3 hr after IN-OT or Placebo (saline) administration. We found significant temporal changes in the functional connectivity between all regions associated with treatment condition. IN-OT increased the functional connectivity between AI_vstr, ACC_amy (right hemisphere), ACC_vstr (left hemisphere), and amy_vstr (right hemisphere), but reduced the functional connectivity between ACC_AI, and the AI_amygdala. These results suggest that IN-OT may dampen salience detection in rhesus monkeys, consistent with previous findings of reduced social vigilance, while enhancing the connectivity between the SN and regions involved in processing reward.