1988 Fiscal Year Final Research Report Summary
Reexamination of lobule I of the cerebellar anterior lobe vermis from a view point of the somatotopical organization
| Project/Area Number |
62570065
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | Nihon University |
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Principal Investigator |
HIRAI Naoki Nihon University School of Medicine, Associate Professor, 医学部, 助教授 (40086583)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Cerebellum / Vestibular reflex / Neck reflex / Postural reflex / Back muscle / ネコ |
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| Research Abstract |
Although being referred to as the tail area, lobule I of the cerebellar anterior lobe vermis has been proved to receive the labyrinthine and neck afferent inputs. This project was made in order to reexamine lobule I from the view point of the somatotopical organization. 1. Spatial distribution of neck, vestibular and tail afferent inputs in lobule I were examined in lobule I after stimulation of these afferents. Convergent inputs through the mossy fibres from the neck and labyrinth were evident. The most responsive area to tail nerve stimulation was in lobule IIb. 2. Properties of vestibulospinal neurones receiving inhibitory influence from lobule I were as follows: 1) They send their axons to lower thoracic or more caudal segments. Only 2 of 30 vestibulocollic neurones were inhibited by lobule I stimulation. 2) They receive convergent excitatory inputs from the neck and labyrinth, that is, common relay neurones of vestibulospinal and neck reflexes. 3) Some of them may act on the motoneurones of the back muscle, because lobule I stimulation depressed the activity of back muscle which could be facilitated from the neck and labyrinth. 4) The lesion made in lobule I by kinic acid produced the disorder of the attitude in animals with similarity to that elicited by neck or vestibular deafferentation, and depressed the placing or hopping reactions. 3. It is supposed that, while receiving convergent inputs of neck and labyrinthine receptors, lobule I may adjust the total activity of the common relay neurones of the two reflexes as to make the resultant output optimal for the stabilization of the body.
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