A new understanding of the association between the hormone secretin and the responsiveness of neurons in the amygdala to emotional stimuli may lead to a treatment for some psychiatric disorders characterized by behavioral problems, according to a presentation at the annual meeting of the American Academy of Neurology.

Studies using magnetic resonance imaging (MRI) methods have found that individuals with a range of behavioral disorders including schizophrenia, depression, bipolar disorder, and autism have abnormal amygdala activation in response to facial emotions and other social stimuli. The amygdala has emerged as one of the most critical areas influencing emotional learning and the attribution of emotional significance to stimuli. The same MRI findings point to amygdala dysfunction as a potential neurobiological factor in the development of these disorders.

Recent evidence suggests that secretin may modulate the functional response of neurons in the amygdala. “We wanted to test the hypothesis that administration of secretin alters amygdala responsiveness to affective stimuli in healthy adult males,” said study author and presenter Deborah Yurgelun-Todd, PhD.

The ability to detect and measure the effects of secretin in the brain is important in three ways. It is consistent with animal studies that report altered amygdala response after secretin administration. It also indicates that administration of this agent can be monitored using neuroimaging methods, therefore providing an important method for studying both brain and behavioral effects of secretin. Finally, and perhaps most promising given the implication of amygdala dysfunction in a variety of behavioral and psychiatric disorders, studies of secretin effects may lead to new treatment interventions for these often debilitating disorders.

“Results of our study support the hypothesis that secretin alters amygdala responsiveness to affective stimuli,” concluded Yurgelun-Todd.