The overall aim of the research is to understand how parallel pathways from retina to cortex are organized and developed in primates. The proposal represents a continuation of studies on the organization and maturation of X-, Y-, and W-like information channels. The three Specific Aims outlined will investigate the adult distinguishing features and postnatal maturation of these pathways.
In Aim I, studies are proposed to confirm and expand knowledge of the basic physiologic and morphologic divisions within the pathways from retina to striate cortex in adult galagos. Receptive field properties of retinal ganglion cells will be examined and compared to those of cell subclasses within the lateral geniculate nucleus (LGN) to determine how information is transformed. The morphology of retinal ganglion cells, LGN cells, and their afferents will be investigated for distinguishing features that correlate with the physiology. Change in W-like LGN cell receptive field properties will also be examined following inactivation of tectal neurons to determine the role of this pathway.
Aim II will examine the development of features uncovered in Specific Aim I as a means of better understanding the adult organization. Studies are outlined that will investigate the maturation of LGN physiology and morphology. Finally, Aim III will test the iplications of hypotheses derived from galago data by comparative studies on galago and two other primate species selected for their distinctive visual system chacteristics. In these studies, cortical visual evoked potentials will be used to define the effect of inactivation of either the parvocellular or magnocellular LGN layers on spatial and temporal contrast sensitivity. Results of these studies should not only add to our understanding of the roles of these channels in vision but also to knowledge about their potential vulnerability to altered postnatal experience.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY001778-11
Application #
3256187
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1978-02-01
Project End
1988-03-31
Budget Start
1986-07-01
Budget End
1988-03-31
Support Year
11
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37203
Jiang, Yaoguang; Purushothaman, Gopathy; Casagrande, Vivien A (2015) A computational relationship between thalamic sensory neural responses and contrast perception. Front Neural Circuits 9:54
Jiang, Yaoguang; Yampolsky, Dmitry; Purushothaman, Gopathy et al. (2015) Perceptual decision related activity in the lateral geniculate nucleus. J Neurophysiol 114:717-35
Jiang, Yaoguang; Purushothaman, Gopathy; Casagrande, Vivien A (2015) The functional asymmetry of ON and OFF channels in the perception of contrast. J Neurophysiol 114:2816-29
Purushothaman, Gopathy; Chen, Xin; Yampolsky, Dmitry et al. (2014) Neural mechanisms of coarse-to-fine discrimination in the visual cortex. J Neurophysiol 112:2822-33
Shostak, Yuri; Wenger, Ashley; Mavity-Hudson, Julia et al. (2014) Metabotropic glutamate receptor 5 shows different patterns of localization within the parallel visual pathways in macaque and squirrel monkeys. Eye Brain 6:29-43
Ichida, Jennifer M; Mavity-Hudson, Julia A; Casagrande, Vivien A (2014) Distinct patterns of corticogeniculate feedback to different layers of the lateral geniculate nucleus. Eye Brain 2014:57-73
Marion, Roan; Li, Keji; Purushothaman, Gopathy et al. (2013) Morphological and neurochemical comparisons between pulvinar and V1 projections to V2. J Comp Neurol 521:813-32
Li, K; Patel, J; Purushothaman, G et al. (2013) Retinotopic maps in the pulvinar of bush baby (Otolemur garnettii). J Comp Neurol 521:3432-50
Purushothaman, Gopathy; Casagrande, Vivien A (2013) A Generalized ideal observer model for decoding sensory neural responses. Front Psychol 4:617
Purushothaman, Gopathy; Marion, Roan; Li, Keji et al. (2012) Gating and control of primary visual cortex by pulvinar. Nat Neurosci 15:905-12

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