Clinical Study Of Monoamine Receptor PET Imaging In Fear Emotion

Frightening music can rapidly arouse emotions in listeners that mimic those from real life-threatening experiences. However, the study on the underlying mechanism for perceiving danger created by music is very limited. Present studies are mainly limited to the structures of brain regions or the simple neurochemical material. The mechanism of related brain regions and the relation of these neurochemical materials are still unknown, and one of the principal reasons is we cannot directly observe the changes of neurochemical messages in the living body. So we select the strong bond monoamine receptor imaging agent (11C-NMSP) to perform Positron Emission Tomography (PET) imaging. Then we can understand the pathological mechanism of PTSD (post trauma stress disorder) from the receptor molecular level through observing the changes of brain receptor of dopamine D2and5-HT2A in the volunteers under fear condition.Part1:Monoamine Receptor PET Imaging Agent and Construction of its TemplateWe selected SPM (Statistical Parametric Mapping) software to analyze the monoamine receptor changes in volunteers. The present templates are only brain blood flow and glucose metabolism, so we have to construct the receptor imaging agent first.20age-matched male volunteers accepted the dynamic PET imaging of one hour. We chose the best imaging time of30min to40min after intravenous injection of agent after compare the ratio of specific region and nonspecific region. Then we acquire the11C-NMSP imaging template from realigning the20images at best time.Part2:Frightening Music Triggers Rapid Changes in Brain Monoamine Receptors:A Pilot PET StudyWe investigated monoamine receptor changes induced by frightening music using the11C-NMSP positron emission tomography (PET) study. Ten male, healthy volunteers were included, and their psychophysiological changes were evaluated. The radioactive accumulations of11C-NMSP were significantly decreased in the bilateral caudate, right limbic and paralimbic regions, especially in the right anterior cingulated cortex, but were increased in the cerebral cortex involving right frontal, occipital lobe and left temporal lobe when subjects had listened to frightening music, compared to a baseline condition.Conclusion:Our results indicate that transient fear emotion in response to frightening music can trigger rapid change monoamine receptors. These findings help to understand the mechanism of brain response to fear emotion.