The long-term goal of the proposed research is the increased understanding of the role of the cerebral cortex in the neural control of eye movement. The major aid during the requested grant period will be the clarification of the interaction of the posterior parietal cortex and the cortex of the frontal eye fields in the control of purposive, visually-guided eye movements. Two general lines of investigation are proposed. In the first, the activity of single neurons in the inferior parietal lobule will be studied in monkeys that have been trained to perform oculomotor and visual attention tasks. The axonal projection targets of neurons in the inferior bank of the intraparietal sulcus will be determined using antidromic activation. The functional properties of neurons which project to the frontal eye fields or the superior colliculus will be characterized. In the course of studying the functional properties of these neurons behavioral tasks which emphasize the performance of visually-evoked saccadic eye movements and also the neural coding of spatial relationships in extrapersonal space will be emphasized. The second are of investigation is a series of neuroanatomical experiments which are directed at discovering the details of the neural connectivity of the parietal association cortex with other cortical and subcortical regions of the brain in monkeys. The anterograde transport of tritiated amino acids and the retrograde transport of two fluorescent dyes will be used to provide new information about the pathways from the frontal eye fields and the inferior parietal lobule to the brainstem oculomotor system that are involved in the control of the visual pursuit of moving objects. These experiments will aid in the understanding of how the brain initiates and controls voluntary eye movements, how that control is impaired by disease and injury, and how the process of partial recovery of function occurs after some strokes and injuries. The results of these studies will increase our understanding of the basic mechanisms of the neural control of behavior, which will in turn aid in the understanding of congenital and acquired disorders of nervous system function. In addition, these studies will eventually contribute to improved tools for diagnosis and for the evaluation of nervous system function in patients following stroke or trauma, and also in the many progressive conditions which are known to affect oculomotor control.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY004159-13
Application #
2159018
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1981-09-01
Project End
1995-03-31
Budget Start
1992-07-01
Budget End
1995-03-31
Support Year
13
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Mississippi Medical Center
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
928824473
City
Jackson
State
MS
Country
United States
Zip Code
39216
Ma, T P; Lynch, J C; Donahoe, D K et al. (1998) Organization of the medial pulvinar nucleus in the macaque. Anat Rec 250:220-37
Tian; Lynch, J C (1997) Subcortical input to the smooth and saccadic eye movement subregions of the frontal eye field in Cebus monkey. J Neurosci 17:9233-47
Tian, J R; Lynch, J C (1996) Functionally defined smooth and saccadic eye movement subregions in the frontal eye field of Cebus monkeys. J Neurophysiol 76:2740-53
Tian, J R; Lynch, J C (1996) Corticocortical input to the smooth and saccadic eye movement subregions of the frontal eye field in Cebus monkeys. J Neurophysiol 76:2754-71
Tian, J R; Lynch, J C (1995) Slow and saccadic eye movements evoked by microstimulation in the supplementary eye field of the cebus monkey. J Neurophysiol 74:2204-10
Lynch, J C; Hoover, J E; Strick, P L (1994) Input to the primate frontal eye field from the substantia nigra, superior colliculus, and dentate nucleus demonstrated by transneuronal transport. Exp Brain Res 100:181-6
Lynch, J C (1992) Saccade initiation and latency deficits after combined lesions of the frontal and posterior eye fields in monkeys. J Neurophysiol 68:1913-6
Hardy, S G; Lynch, J C (1992) The spatial distribution of pulvinar neurons that project to two subregions of the inferior parietal lobule in the macaque. Cereb Cortex 2:217-30
Lynch, J C; McLaren, J W (1989) Deficits of visual attention and saccadic eye movements after lesions of parietooccipital cortex in monkeys. J Neurophysiol 61:74-90
Lynch, J C (1987) Frontal eye field lesions in monkeys disrupt visual pursuit. Exp Brain Res 68:437-41

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