title: Oxytocin affects the connectivity of the precuneus and the amygdala: a randomized, double-blinded, placebo-controlled neuroimaging trial.
abstract: BACKGROUND
  Although oxytocin is one of the most widely studied neuropeptides in recent times, the mechanistic process by which it modulates social-affective behavior in the brain is not yet clearly understood. Thus, to understand the neurophysiological basis of oxytocin effects, we used resting-state functional MRI to examine the effects of intranasal oxytocin on brain connectivity in healthy males.
  
  
  METHODS
  Using a randomized, double-blinded, placebo-controlled, crossover design, 15 healthy male volunteers received 24 IU intranasal oxytocin or placebo prior to resting-state functional MRI acquisition at 3T.
  
  
  RESULTS
  We found that oxytocin significantly reduced the degree centrality of the right precuneus (P<.05). Oxytocin also reduced connectivity between the bilateral amygdalae and between the right precuneus and the right and left amygdala (P<.05). Although there were no significant changes in regional homogeneity at the whole brain level, posthoc results showed a reduction involving the right precuneus (P<.05).
  
  
  CONCLUSIONS
  These results show that oxytocin affects one of the key centers in the brain for social cognition and introspective processing, the precuneus, and enhances our understanding of how oxytocin can modulate brain networks at rest. An improved understanding of the neurophysiological effects of oxytocin can be important in terms of evaluating the mechanisms that are likely to underlie the clinical responses observed upon long-term oxytocin administration.
authors.affiliation: Translational Neuroimaging in Mental Health, Division of Psychiatry and Applied Psychology, University of Nottingham, Nottingham, United Kingdom (Ms Kumar, Dr Völlm, and Dr Palaniyappan); Nottinghamshire Healthcare NHS Trust, Nottingham, United Kingdom (Drs Völlm and Palaniyappan).
authors.forename: Jyothika
authors.initials: J
authors.lastname: Kumar
authors.affiliation: Translational Neuroimaging in Mental Health, Division of Psychiatry and Applied Psychology, University of Nottingham, Nottingham, United Kingdom (Ms Kumar, Dr Völlm, and Dr Palaniyappan); Nottinghamshire Healthcare NHS Trust, Nottingham, United Kingdom (Drs Völlm and Palaniyappan).
authors.forename: Birgit
authors.initials: B
authors.lastname: Völlm
authors.affiliation: Translational Neuroimaging in Mental Health, Division of Psychiatry and Applied Psychology, University of Nottingham, Nottingham, United Kingdom (Ms Kumar, Dr Völlm, and Dr Palaniyappan); Nottinghamshire Healthcare NHS Trust, Nottingham, United Kingdom (Drs Völlm and Palaniyappan). Lena.Palaniyappan@nottingham.ac.uk.
authors.forename: Lena
authors.initials: L
authors.lastname: Palaniyappan
mesh_terms: D000281:Administration, Intranasal / Q000379:methods; D000328:Adult; D000679:Amygdala / Q000187:drug effects* / Q000502:physiology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000187:drug effects* / Q000502:physiology*; D059906:Neuroimaging / Q000379:methods; D009479:Neuropeptides / Q000494:pharmacology; D010121:Oxytocin / Q000008:administration & dosage / Q000494:pharmacology*; D010296:Parietal Lobe / Q000187:drug effects* / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D009479:Neuropeptides; D010121:Oxytocin
keywords: amygdala; fMRI; oxytocin; precuneus; resting-state