***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Trust pervades human societies . Trust is indispensable in friendship , love , families and organizations , and plays a key role in economic exchange and politics . In the absence of trust among trading partners , market transactions break down . In the absence of trust in a country 's institutions and leaders , political legitimacy breaks down . Much recent evidence indicates that trust contributes to economic , political and social success . Little is known , however , about the biological basis of trust among humans . Here we show that intranasal administration of oxytocin , a neuropeptide that plays a key role in social attachment and affiliation in non-human mammals , causes a substantial increase in  trust among humans , thereby greatly increasing the benefits from social interactions . We also show that the effect of oxytocin on trust is not due to a general increase in the readiness to bear risks . On the contrary , oxytocin specifically affects an individual 's willingness to accept social risks arising through interpersonal interactions . These results concur with animal research suggesting an essential role for oxytocin as a biological basis of prosocial approach behaviour BACKGROUND In nonhuman mammals , oxytocin has a critical role in peer recognition and social approach behavior . In humans , oxytocin has been found to enhance trust and the ability to interpret the emotions of others . It has been suggested that oxytocin may enhance facial processing by increasing focus on the eye region of human faces . METHODS In a double-blind , r and omized , placebo-controlled , between-subject design , we tracked the eye movements of 52 healthy male volunteers who were presented with 24 neutral human faces after intranasal administration of 24 IU oxytocin or placebo .  RESULTS Participants given oxytocin showed an increased number of fixations and total gaze time toward the eye region compared with placebo participants . CONCLUSIONS Oxytocin increases gaze specifically toward the eye region of human faces . This may be one mechanism by which oxytocin enhances emotion recognition , interpersonal communication , and social approach behavior in humans . Findings suggest a possible role for oxytocin in the treatment of disorders characterized by eye-gaze avoidance and facial processing deficits Autism is a neurodevelopmental disorder characterized by dysfunction in three core behavioral domains : repetitive behaviors , social deficits , and language abnormalities . There is evidence that abnormalities exist in peptide systems , particularly the oxytocin system , in autism spectrum patients . Furthermore , oxytocin and the closely related peptide vasopressin are known to play a role in social and repetitive behaviors . This study examined the impact of oxytocin on repetitive behaviors in 15 adults with autism or Asperger 's disorder via r and omized double-blind oxytocin and placebo challenges . The primary outcome measure was an instrument rating six repetitive behaviors : need to know , repeating , ordering , need to tell/ask , self-injury , and touching .  Patients with autism spectrum disorders showed a significant reduction in repetitive behaviors following oxytocin infusion in comparison to placebo infusion . Repetitive behavior in autism spectrum disorders may be related to abnormalities in the oxytocin system , and may be partially ameliorated by synthetic oxytocin infusion BACKGROUND The presence of social support has been associated with decreased stress responsiveness . Recent animal studies suggest that the neuropeptide oxytocin is implicated both in prosocial behavior and in the central nervous control of neuroendocrine responses to stress . This study was design ed to determine the effects of social support and oxytocin on cortisol , mood , and anxiety responses to psychosocial stress in humans . METHODS In a placebo-controlled , double-blind study , 37 healthy men were exposed to the Trier Social Stress Test . All participants were r and omly assigned to receive intranasal oxytocin ( 24 IU ) or placebo 50 min before stress , and either social support from their best friend during the preparation period or no social support . RESULTS Salivary free cortisol levels were suppressed by social support in response to stress . Comparisons of pre- and poststress anxiety levels revealed an anxiolytic effect of oxytocin . More importantly , the combination of oxytocin and social support exhibited the lowest cortisol concentrations as well as increased calmness and decreased anxiety during stress . CONCLUSIONS Oxytocin seems to enhance the buffering effect of social support on stress responsiveness . These results concur with data from animal research suggesting an important role of oxytocin as an underlying biological mechanism for stress-protective effects of positive social interactions Oxytocin ( OXT ) and ghrelin have several common properties such as the involvement in the first phase response to stressors , in appetite regulation , and in the modulation of neural functions . Despite a recent study showing that intraventricular administration of ghrelin activates OXT neurons , little is known on the cross-talk between these two peptides . Here , we investigated the role of the i.v . administration of OXT on circulating ghrelin concentrations under fasting conditions and during the lipopolysaccharide (LPS)-induced endotoxemia . A r and omized placebo-controlled cross-over study was performed in ten healthy men . In four study sessions , the participants received once placebo , once OXT ( 1 pmol/kg per min over 90 min ) , once LPS ( 2 ng/kg ) , and once both OXT and LPS .  Plasma ghrelin , glucose , and free fatty acid ( FFA ) levels were measured at regular intervals during the first 6 h following the LPS bolus . Systemic administration of OXT decreased within 1 h plasma ghrelin levels ( 611+/-54 vs 697+/-52 pg/ml in placebo days , P=0.013 ) and increased plasma glucose and FFA concentrations ( P=0.002 and P=0.005 respectively ) . OXT also reduced the LPS-induced surge in ghrelin at time point 2 h ( P=0.021 ) . In summary , i.v . administration of OXT decreases circulating levels of ghrelin during fasting , as well as following LPS-induced endotoxemia in healthy men . The cross-talk between OXT and ghrelin might be important in the regulation of energy homeostasis and stress responses BACKGROUND A diagnostic hallmark of autism spectrum disorders is a qualitative impairment in social communication and interaction . Deficits in the ability to recognize the emotions of others are believed to contribute to this . There is currently no effective treatment for these problems . METHODS In a double-blind , r and omized , placebo-controlled , crossover design , we administered oxytocin nasal spray ( 18 or 24 IU ) or a placebo to 16 male youth aged 12 to 19 who were diagnosed with Autistic or Asperger 's Disorder . Participants then completed the Reading the Mind in the Eyes Task , a widely used and reliable test of emotion recognition . RESULTS In comparison with placebo , oxytocin administration improved performance on the Reading the Mind in the Eyes Task . This effect was also shown when analysis was restricted to the younger participants aged 12 to 15 who received the lower dose . CONCLUSIONS This study provides the first evidence that oxytocin nasal spray improves emotion recognition in young people diagnosed with autism spectrum disorders . Findings suggest the potential of earlier intervention and further evaluation of oxytocin nasal spray as a treatment to improve social communication and interaction in young people with autism spectrum disorders 
    Output:
    
The existing literature , although limited and based on small sample sizes , suggests a derangement of the OT system in AN that may normalise upon recovery .
Preliminary pilot data from unpublished studies suggest a potential effect of OT administration on eating-related indices