2004 Fiscal Year Final Research Report Summary
Effects of transcranial magnetic stimulation on a reflex myoclonus model in rats
| Project/Area Number |
14570602
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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 |
Neurology
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| Research Institution | Kagawa University |
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Principal Investigator |
TOUGE Tetsuo Kagawa University, School of Medicine, Health Sciences, Associate Professor, 医学部, 助教授 (80197839)
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| Co-Investigator(Kenkyū-buntansha) |
DEGUCHI Kazushi Kagawa University, Third Department of Internal Medicine, Instructor, 医学部附属病院, 講師 (80263896)
TSUKAGUCHI Masago Kagawa University, Third Department of Internal Medicine, Research Assistant, 医学部附属病院, 助手 (60335867)
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| Project Period (FY) |
2002 – 2004
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| Keywords | repetitive electric brain stimulation / repetitive magnetic brain stimulation / somatosensory evoked potentials / reflex myoclonus / rat / histological analysis |
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| Research Abstract |
Objects : Since the mechanism that repetitive electric (rES) and transcranial magnetic stimulation (rTMS) transiently modulate cortical neuron excitabilities is not clear, we studied the effects of rES and rTMS on somatosensory evoked potentials (SEPs) in rats. In addition, we studied the effects of rES on cortical reflex myoclonus in catechol-induced myolonus rats.
Subjects and Methods : After anesthetizing rats, a pair of burr holes was drilled in the skull over the right somatosensory area for the hindlimb. rES was performed with a frequency of 1 or 0.2 Hz for 3 hours and 20 minutes using two stainless screws inserted into the burr holes. The right somatosensory areas were magnetically stimulated with a frequency of 1 Hz for 2 hours and 20 minutes using a small eight-figure coil. SEPs elicited by stimulating the left hindlimb was recorded before and after rES or rTMS. Amplitudes and latencies of SEP components were measured and compared between the rES or rTMS and control groups. After 25Hz-rES for 30 minutes to the somatosensory area, catechol was intraperitoneally injected (80mg/kg) to rats. Onset times and durations of catechol-induced myoclonus were measured. Changes of SEP components were also observed before and after injection of catechol.
Results : Amplitudes of cortical components of SEPs were significantly reduced after rES or rTMS compared with those in the control. Immunohistological analysis showed that c-Fos expression was observed in cortical neurons stimulated by rES. There is no other histological change by rES or rTMS. rES did not significantly affect catechol-induced myoclonus and SEPs.
Conclusion : The present results support that rES and rTMS have similar effects on cortical neurons excitabilities. Histological changes were simultaneously shown by immunohistological analysis using anti-c-Fos antibody. However, effects of rES on catechol-induced myoclonus remained to be solved.
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