In the PI's working model of visual information processing, three segregated parallel pathways (magnocellular (M), parvicellular (P), and koniocellular (K)) from the lateral geniculate nucleus (LGN) to primary visual cortex (V1) are utilized by the laminar and compartmental (i.e. cytochrome oxidase (CO) blob and interblob) circuitry of V1 to synthesize new output pathways appropriate for the next steps of analysis. Within this scheme, separate output layers and compartments of V1 have distinct modes for integrating signals from all three input pathways and generating output signals that support extrastriate areas, specialized not for specific attributes, but for more complex visual analysis. In light of this model, the project's broad aims are to test the significance of these pathways, define how input pathways engage the circuitry of V1 layers and compartments, and discern the strategies utilized by the output pathways to support V1 target areas. This proposal focuses on the K and the M input pathways and on output pathways to visual area 2 (V2), the dorsal medial visual area (DM), and the middle temporal visual area (MT).
The specific aims are designed to test hypotheses generated by our working model.
In Aim I, the PI will examine the K pathway and how this and other pathways are integrated within the CO-blobs of V1.
In Aim II, she will determine the relationship of LGN K (or M) cell activity to eye movements or to behavioral relevance.
In Aim III she will define the organization of V1 output pathways from CO-blob columns. The results of this proposed studies will contribute important new information to the fundamental understanding of how the brain processes visual information and of brain architecture in general.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY001778-25
Application #
6384277
Study Section
Special Emphasis Panel (ZRG1-VISA (01))
Program Officer
Oberdorfer, Michael
Project Start
1978-02-01
Project End
2003-03-31
Budget Start
2001-04-01
Budget End
2002-03-31
Support Year
25
Fiscal Year
2001
Total Cost
$349,389
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

Showing the most recent 10 out of 73 publications