2013 Fiscal Year Final Research Report
The interaction between serotonergic and cannabinoidergic neurotransmissions in the basolateral amygdala
| Project/Area Number |
24791192
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Psychiatric science
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| Research Institution | Hokkaido University |
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Principal Investigator |
YOSHIDA Takayuki 北海道大学, 医学(系)研究科(研究院), 助教 (60374229)
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| Co-Investigator(Renkei-kenkyūsha) |
WATANABE Masahiko 北海道大学, 医学研究科, 教授 (70210945)
TANAKA Kenji 慶応大学, 医学部, 准教授 (30329700)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 扁桃体 / セロトニン / カンナビノイド / 恐怖記憶 |
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| Research Abstract |
In this study, we found predominant neuronal projections of serotonergic, dopaminergic and cholinergic fibers in the basolateral amygdala (BLA), and CB1 receptor was frequently localized on serotonergic axon but not dopaminergic, noradrenergic or cholinergic fibers. Furthermore, extracellular release of serotonin was significantly reduced by WIN55212-2, CB agonist, whereas dopamine concentration was not altered, indicating presynaptic serotonin release is modulated by CB1 receptors. On the other hand, alpha-methyl-5-HT, 5-HT2 receptor agonist triggered postsynaptic endocannabinoid synthesis and induced the reduction of presynaptic GABA release. This suppression was completely blocked by MDL100907, 5-HT2A antagonist, or AM251, CB1 antagonist. These findings suggest that endocannabinoid is synthesized via activation of postsynaptic 5-HT2A receptors, and regulates on-demand local serotonergic transmission in the BLA, as well as neuronal activation of dorsal raphe nucleus.
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