Increased amygdala fMRI activation after secretin administration
Deborah A Yurgelun-Todd1, Jadwiga Rogowska, Staci A Gruber
1Neuroimaging Laboratory, McLean Hospital/Harvard Medical School, Belmont, MA 02478-9106, USA. ytodd@mclean.harvard.edu
Experimental and Clinical Psychopharmacology
|June 11, 2008
Summary
Secretin infusion increased right amygdala activation in humans viewing fearful faces, suggesting a role in processing negative emotions and social behavior modulation.
Area of Science:
- Neuroscience
- Psychiatry
- Molecular Biology
Background:
- Secretin is known to activate gene expression in the central nucleus of the amygdala in rats.
- Understanding secretin's neurophysiological effects in humans is crucial for its potential therapeutic applications.
Purpose of the Study:
- To investigate the neurophysiological effects of secretin on amygdalar activation in humans during facial affect processing.
- To determine if secretin influences brain responses to different emotional stimuli.
Main Methods:
- A placebo-controlled, double-blind study involving 12 healthy males.
- Blood Oxygen Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) was used to measure brain activity.
- Participants viewed happy, fearful, and neutral faces before and after secretin or placebo infusion.
Main Results:
- Secretin infusion led to significant activation in the right amygdala (p=.001) during the viewing of fearful faces compared to placebo.
- No significant differences in amygdala activation were observed for happy or neutral faces between secretin and placebo conditions.
- A nonsignificant increase in left amygdala activation was noted during the fear condition with secretin.
Conclusions:
- Secretin may alter human responsivity to affective stimuli, particularly negative ones.
- Increased amygdala activation by secretin during fear processing aligns with animal studies.
- These findings suggest a potential mechanism for secretin in modulating social behavior.
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