tn our working model of visual information pro cessing, we hypothesize that there are three segregated paraIlet pathways [magnocell utar (M), parvocetlular (P), and koniocelIutar (K)] from the laterat genicuI ate nucteus (LGN) to primer y visual cortex (V1), form ing both dedicated and multi-functional systems and networks. Within this scheme, separate output layer s and compartments of V1 have distinct modes for utilizing signals from eli three input pathways and generating output signals that contribute to the dynamics and functional maps of extrastriate areas. tn light of this model, the major effort of our project is to understand how parallel LGN pathway s in primates contribute to the properties of V1 and its extrastriate targets. This proposal focuses on all three LGN relays and how their inputs affect V 1 and higher visual centers, but places added em phasis on the K pathway considering the fact that it has been, until recently, largely ignored.
Our specific aims are designed to test hypotheses generated by our working modet.
In Aim I, we will determine the number of physiologically distinct K channels and the classes of retinal gangtion ceils that project to K LGN layers.
In Aim II, we wilt determine the relationship between LGN relay cells and the dynamics and functional maps found within V 1.
In Aim tit, we will apply the same techniques Jtilized in Aim II to determine how LGN relays contribute to the dynamics and functional maps found wi thin extrastfiate areas V2, V3, and DM/V3a. The results of our proposed studies wilI contribute important new nformation to our understanding of the fundamentals of how the brain processes visual information and of _rain architecture in general.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
3R01EY001778-31S1
Application #
7585933
Study Section
Visual Sciences B Study Section (VISB)
Program Officer
Oberdorfer, Michael
Project Start
1978-02-01
Project End
2009-03-31
Budget Start
2007-04-01
Budget End
2009-03-31
Support Year
31
Fiscal Year
2008
Total Cost
$42,707
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
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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