Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants |
|Research Institution||Tokyo Medical and Dental University |
KATAYAMA Yoshifumi Tokyo Medical and Dental University, Professor, 難治疾患研究所, 教授 (20014144)
MARTIN I. Universidad Complutense de Madrid, 医学部, Prof titul
NORTH R.A. Oregon Health Sciences University, 教授
LEES G.M. University of Aberdeen, 医学部, Reader
TSUJI S. University of Paris VI (Universite Pierre et Marie Curie), Research D
三原 智 久留米大学, 医学部, 助手 (40166103)
西 彰五郎 久留米大学, 医学部, 教授 (00080557)
辰巳 仁史 東京医科歯科大学, 難治疾患研究所, 助手 (20171720)
平井 恵二 東京医科歯科大学, 難治疾患研究所, 助教授 (70156628)
NISHI S. Kurume University
MIHARA S. Kurume University
HIRAI K. Tokyo Medical and Dental University
TATSUMI H. Tokyo Medical and Dental University
NORTH R A オレゴン健康科学大学, Vollum研究所, 教授
|Project Period (FY)
1992 – 1993
Completed(Fiscal Year 1993)
|Budget Amount *help
¥11,500,000 (Direct Cost : ¥11,500,000)
Fiscal Year 1993 : ¥5,500,000 (Direct Cost : ¥5,500,000)
Fiscal Year 1992 : ¥6,000,000 (Direct Cost : ¥6,000,000)
|Keywords||Distributed control system / Enteric nervous system / Myenteric plexus / Submucous plexus / Neuroactive substances / Synaptic transmission / Growth cone / Neural net / アウェルバッハ神経叢 / マイスナー神経叢 / 神経伝達 / 成長錐 / GTP結合蛋白 / カルシウム|
Reports from all investigators are summarized as follows.
It was demonstrated that the ability of provoking peristalsis, though impaired, could be preserved in the isolated guinea-pig ileum from which both mucosa and submucosa were mechanically removed. ATP and L-DOPA modulated transmitter release in the enteric nervous system of the guinea-pig ileum and caecum.
In the in vitro models of intestinal ischaemia using guinea-pigs, only a few myenteric neurons showed the 'classical' neuronal membrane response indicative of ischaemic damage, whereas other myenteric and submucous neurons showed no change in their electrical properties or synaptic transmission.
Neuropeptide Y (NPY, 1-100 nM) was found to inhibit the slow IPSPs in the caecum submucous plexus of guinea-pigs ; NPY did not affect the electrophysiological properties nor the response of the cells to noradrenaline, the mediator for the slow IPSPs. Moreover, up to 300 nM, NPY had no detectable effect on the fast and slow EPSPs. Thus, NPY might act only presynaptically and selectively to depress noradrenaline release. The slow IPSPs were rare events in neurons of the descending colon, compared with the caecum. This is preliminary evidence for another important example of regional differences in the function of the enteric neurons.
Cholinergic neurons of the diagonal band of Broca were isolated from fetus or new-born rats and were kept in culture. Histo- and immunocytochemical invesstigations on these neurons disclosed the presence of cholinergic metabolism in growth cones at high level even before synapse-formation. Rapid elongation of filopoida from growth cones was observed in response to high potassium stimulation. Con-A-coated gold particles possibly attached to growth cone membrane moved apparently in a Brownian manner within some restricted area, and their movement could be controlled by means of laser tweezers.