1997 Fiscal Year Final Research Report Summary
NEUROPHYSIOLOGICAL STUDY OF THE CENTRAL NERVOUS SYSTEM OF THE NEAR RESPONSE
| Project/Area Number |
08672027
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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 |
Ophthalmology
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| Research Institution | SAPPOROMEDICAL UNIVERSITY |
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Principal Investigator |
OHTSUKA Kenji SAPPORO MEDICAL UNIVERSITY,DEPARTMENT OF OPHTHALMOLOGY,ASSOCIATE PROFESSOR, 医学部, 助教授 (60203832)
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| Project Period (FY) |
1996 – 1997
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| Keywords | SUPERIOR COLLICULUS / ACCOMMODATION / VERGENCE / NEAR RESPONSE / FIXATION / PRETECTUM / OMNIPIUSE NEURON / CAT |
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| Research Abstract |
The superior colliculus (SC) has long been recognized as an important structure in the generation of saccadic eye movements. The SC of the cat and the monkey has recently been shown to be involved in the control visual fixation. A subpopulation of collicular cells exhibits tonic discharge when the animal fixates on a target of interest. These cells are located in the rostral SC where the central visual field is represented. Active fixation is thought to be important for the ocular near response ; accommodation, vergence and pupillo-constriction, and these systems are functionally linked. Therefore, it is possible that the rostral SC is also involved in the control of accommodation or vergence. The results of several recent studies have suggested that the rostral SC is also involved in the control of accommodation. The accommodation-related area in the rostral SC also corresponds to the area of representation of the cental visual field. The accommodation-related area in the SC receives heavy projections from the accommodation area in the lateral supasylvian (LS) area of the cat cortex. It is well known that the LS area is also involved in the control of vergence and pupillo-constriction. The rostral SC projects to the pretectal nuclei (PT) where accommodative responses are evoked by microstimulation, the raphe interpositus (RIP), in which omnipause neurons are located, and the dorsomedial portion of the nucleus reticularis tegmenti pontis. Many neurons in the intermediate layrs of the rostral SC have divergent axon collaterals to the PT and the RIP.The rostral SC is likely a key structure involved in the near response and visual fixation.
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