1991 Fiscal Year Final Research Report Summary
Mechanism of nervous interaction between the enteric nervous system and the autonomic nervous system
| Project/Area Number |
02044134
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Tokai University |
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Principal Investigator |
TAMURA Kenji Tokai University, School of Medicine Department of Physiology I, 医学部・生理学I教室, 講師 (20163686)
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| Co-Investigator(Kenkyū-buntansha) |
SCHEMANN Michael Institute fur Zoophysiology, Hohemheim University, Universtity o, 助教授
WOOD Jackie D. Department of Physiology, The Ohio State University, The Ohio State, 主任教授
KUWAHARA Atsukazu National Institute of Physiological Science, 生理学研究所, 助手
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| Project Period (FY) |
1990 – 1991
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| Keywords | enteric nervous system / myenteric plexus / autonomic nervous system / morphology vagus nerve / pelvic nerve / C fiber / 胃 / FastーEPSPs |
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| Research Abstract |
This project has been designed to investigate the synaptic relationships between the myenteric plexus in the guinea pig stomach, small intestine, distal colon and rectum and the extrinsic autonomic innervations to these parts of the gastrointestinal tract. In order to address this final target, two experimental steps have been made. As a first step, stomach or distal colonic myenteric neurons were stained intracellularly with Lucifer yellow or neurobiotin to Characterize the cellular morphology. Two morphological cell types were identified in the distal colon. One was neurons with a single long process (SLP) and multiple short processes in various forms and the other was neuron which had multiple long process (MLP) emanating a oval smooth surfaced cell body with or without short processes. Electrical properties of MLP neurons were always those of the AH/type II neurons but SLP neurons showed various characteristics those of including AH/type 2, S/typo 1, Single spike and Type 3 neurons. In the stomach myenteric plexus, no MLP neuron was found and all of the neurons showed short spike durations. In the next step of the project, intracellular recordings were made from stomach and distal colonic myenteric neurons while vagus and pelvic nerves were stimulated extracellularly. Synaptic potentials evoked by extrinsic nerve stimulations were only fast excitatory postsynatpic potentials (fast-EPSPs) with long time delays. No slow synaptic input was found either stomach or distal colonic myenteric plexus. In the colonic myenteric plexus fast-EPSPs were found only in the SLP neurons which had shorter spike duration than MLP neurons. It appeared that extrinsic excitatory inputs from central nervous system to the myenteric plexus were medicated by C fibers in the form of fast-EPSPs and only to the SLP neurons.
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