| Project/Area Number |
08671733
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
ADACHI Takehiko Kyoto University Hospital, Department of Critical Care Medicine, Lecturer, 医学研究科, 講師 (90252428)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAO Shinichi Kansai Medical College, Department of Anesthes, Lecturer, 医学部, 講師 (10207714)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Spinal Cord / Wide Dynamic Range Neuron / Wind Up / carrageenan / carageenan |
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| Research Abstract |
We have investigated the effect of halothane on the expansion of the receptive field of the wide dynamic range (WDR) neuron in the spinal cord of cats. The expansion was induced by the injection of an inflammatory agent, carrageenan (CG), into the center of peripheral receptive field of WDR neuron, usually hindpaw. Cats were anesthetized by urethane and chloralose, underwent lumbar laminectomy. A glass microelectrode filled with 3M KCl was inserted into the spinal cord. The activity of spinal dorsal horn neurons were identified by observing oscilloscope and hearing the sound responded to peripheral tactile stimulation of a hindpaw. Then we decided the character of the neuron by giving mechanical innocuous and nociceptive stimulation or heat stimulation. Neurons which responded to all stimulus modality and the response of which to mechanical stimulation increased gradually in proportion to the strength of applied stimuli were regarded as WDR neurons. The receptive field was decided by giving innocuous mechanical stimulation using brush. In the control group, the receptive field began to expand 2 hours after the injection of CG (20mg), reached maximum at 4 hours and remained maximum level until 6 hours after injection. In halothane group, 0.5% halothane was inhaled from 20 min before CG injection until 2 hours after CG injection. The receptive field was slightly smaller than baseline during halothane inhalation. The receptive field began to expand 2 hours after halothane discontinuation (4 hours after CG injection) and reached maximum at 4 hours after the end of halothane inhalation (6 hours after CG injection). The level of expansion was similar to that of control group finally. These results suggest that halothane inhibits the expansion of receptive field of WDR neuron induced by the injection of CG,but this effect is limited during its inhalation.
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