1989 Fiscal Year Final Research Report Summary
Control mechanisms of orienting movements of the head in the vertical direction.
| Project/Area Number |
63480104
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurophysiology and muscle physiology
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| Research Institution | Faculty of Medicine, University of Tokyo |
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Principal Investigator |
SASAKI Shigeto Faculty of Medicine, Department of Neurophysiology, Institute of Brain Res., University of Tokyo, Associate Professor, 医学部(医), 助教授 (50110490)
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| Co-Investigator(Kenkyū-buntansha) |
IWAMOTO Yoshiki Faculty of Medicine, Department of Neurophysiology, Institute of Brain Research,, 医学部(医), 助手 (50184908)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Forel's Field H / Orienting Movements / Head / Vertical |
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| Research Abstract |
Forel's field H (FFH) is located in the mesodiencephalic junctional area, rostrodorsal to the red nucleus. Almost all FFH neurons projected to the pontomedullary reticular formation and about half of them further to upper cervical cord. FFH neurons exert excitatory effects on dorsal neck motoneurones both monosynaptically and disynaptically through reticulospinal neurons in the pons and medulla. The effects were almost exclusively to head elevator muscles (biventer cervicis and complexus). Cats were trained to make orienting movements. They stand in front of a perimeter on which 7 light emitting diodes (LEDS) were arrange horizontally and 12 LEDs vertically. When cats, fixating a center LED which had been turned on, direct heads and fixate a new peripheral LED which turned on immediately after switching off the center LED, they were rewarded with a small peace of meet from a small hole opened beneath the LED. Orienting movements of the head in the vertical direction were consist of three components. Neck rotation in which head rotated at neck and trunk joint, head rotation in which heads rotated at the atlanto-occipital joint. Parallel shifts in which the head was lifted or lowered parallelly mainly by forelimb movements.
Angular velocity of head movements related linearly to the total amplitudes of head movements. Following bilateral injection of kainic acid into FFH, tonic activity of neck and trunk muscles, increased dramatically for 10-20 hours, decreased for about 70 hours and then recovered.
Cats could direct head and eyes to LEDs in the horizontal direction but not in the vertical direction. Cats gradually managed to make orienting movements in vertical direction mainly by parallel shifts. These results suggested that FFH is a premotor center controlling vertical head movements.
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Research Products
(17 results)
