Morphological studies for neurotransmission in the trigeminal nervous system -Roles of neuropeptides and amino acid-.
Project/Area Number |
02454464
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
外科・放射線系歯学
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Research Institution | Osaka Dental University |
Principal Investigator |
UEDA Yutaka Osaka Dental University, Faculty of Dentistry, Professor, 歯学部, 教授 (10067001)
|
Co-Investigator(Kenkyū-buntansha) |
ADACHI Hiroyasu Osaka Dental University, Faculty of Dentistry, Assistant, 歯学部, 助手 (40140206)
|
Project Period (FY) |
1990 – 1992
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Project Status |
Completed (Fiscal Year 1992)
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Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1992: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1991: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1990: ¥5,200,000 (Direct Cost: ¥5,200,000)
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Keywords | Trigeminal nucleus / Galanin / Dynorphin / Tachykinin / Glutamate / GABA / mRNA / C-fos / C-fos / 三叉神経脊髄路核 / 疼痛刺激 / ペプチド前駆体 mRNA / in situハイブリダイゼイション法 / ラット / 三叉神経系 / 神経伝達物質 / グルタメ-ト / 疼瘍刺激 / in situ ハイブリダイゼ-ション / エンケファリン |
Research Abstract |
Changes in the levels of transcription factor mRNA and neuropeptide precursor mRNA in the trigeminal nucleus caudalis (TNC) in response to orofacial pain induced by the injection of formalin into the facial skin of anesthetized rats were investigated. After the injection of formalin, the number of neurons expressing c-fos, NGFI-A and NGFI-B mRNA was increased, followed by increases in the number of neurons expressing preprogalanin (PPG), preproenkephalin A (PPEA), preprodynorphin (PPD) and preprotachykinin (PPT) mRNA in the superficial layers (laminae I and II) of the ipsilateral TNC in accordance with the projection system previously described. The increases in the number and intensity of the labeled neurons for PPG, PPEA, PPD and PPT mRNA were most marked 6 hrs after the injection of formalin. The increases in the number and intensity of the labeled neurons for c-fos, NGFI-A and NGFI-B mRNA were most marked at 2 hrs. Furthermore, the numbers of PPD and PPT mRNA containing neurons were
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increased in the contralateral TNC after the injection. The number of Fos-like immunoreactivity positive neurons was also increased in the contralateral TNC. These findings suggested that the modulation of pain is associated with the increased production of PPG, PPE, PPD and PPT, and the transcription of these genes are regulated by immediate early genes, such as c-fos, NGFI-A and NGFI-B. Noxious information seems to affect neurons in the contralateral TNC, as well. The distribution study of glutamate-like (GLU-LI) and glutaminase-like (GLNase-LI) immunoreactivity (IR) combined with tracer method showed that trigeminal neurons projecting to the thalamus and cerebellum constitute distinct subpopulations, and that some of these neurons are glutamatergic. Furthermore, NMDAR_1, GluR_2 and GluR_5 subunit mRNAs of glutamate receptor and beta_2,gamma_1 and gamma_2 subunit mRNAs of GABA_A receptor were found in the trigeminal ganglion. These findings indicate that primary sensory neurons are presynapticaly regulated by glutamate and GABA in the TNC. Less
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Report
(4 results)
Research Products
(9 results)