1996 Fiscal Year Final Research Report Summary
Neuroscientific studies on brain mechanisms of learning of tastes
| Project/Area Number |
07457438
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional basic dentistry
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| Research Institution | Osaka University |
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Principal Investigator |
YAMAMOTO Takashi Osaka Univ., Fac.Human Sci., Proffesor, 人間科学部, 教授 (60028793)
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| Co-Investigator(Kenkyū-buntansha) |
SAKO Noritaka Osaka Univ., Fac.Human Sci., Res. Associate, 人間科学部, 助手 (90243154)
SHIMURA Tsuyoshi Osaka Univ., Fac.Human Sci., Assistant Proffesor, 人間科学部, 講師 (80150332)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Taste / Learning / Brain / Neuroscience |
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| Research Abstract |
As a model of learning of taste, the conditioned taste aversion (CTA) paradigm w as used. CTA was established in Wistar male rats by an intraperitoneal injection of 0.15 M LiCl (US) soon after free drinking of 0.005 M saccharin (CS). The following results were obtained.
1.Behavioral study
Bilaterallesions of the zona incerta attenuated the acquisition and retention of CTA.Lesions of the cetral amygdaloid nucleus disrupted aversive behaviors, but lesions of the basolateral nucleus interrpted with avoidance behaviors.
2.Electrophysiological study
When the rats were trained to avoid HCl, They avoided other acids such as malic acid, citric acid and tartaric acid. Responses of the parabrachial neurons to there acids in CTA-trained rats were larger than those in control rats.
3.c-Fos study
Expression of proto-oncogene c-fos w as immunohistochemically examined in the central and basolateral amygdaloid nuclei in rats. The intraoral infusion of sucrose, but not of saccharin, elicited intense c-fos expression in the central nucleus after establishment of conditioned taste aversion to these taste stimuli.
4.Neurochemical study
The glutamate level in the ventromedial globus pallidus (vGP) increased in response to intraoral infusions of various fluids and voluntary ingestion of food pellets. Palatable fluids evoked greater responses than unpalatable fluids did, suggesting that glutamate in the vGP is involved in specific motivational regulation of ingestive behavior.
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