Establishing how the response properties of neurons in visual cortex emerge from the synaptic interactions of distinct circuit elements remains one of the fundamental challenges for visual neuroscience and is central to understanding the neural basis of visual perception and disorders of visual function. The experiments in this proposal continue our analysis of the functional organization of circuits in layer 2/3 of visual cortex by employing state of the art techniques to determine how the well-developed network of horizontal connections within layer 2/3 interacts with feedforward inputs from cortical layer 4 to shape the visual response properties of layer 2/3 neurons.
The first aim employs in vivo 2-photon imaging of calcium signals in combination with retrograde labeling techniques to determine, with single cell resolution, the visual response properties of the neurons that contribute to the horizontal network in layer 2/3.
The second aim employs in vivo optogenetic control of the activity of layer 2/3 neurons to assess how modulating the activity of horizontal inputs impacts the visually driven responses of layer 2/3 neurons. In the final aim, optogenetic techniques will be combined with in vivo intracellular recordings to assess the synaptic interactions that account for the contribution of horizontal connections to the response properties of layer 2/3 neurons. Taken together, these experiments should provide a wealth of new insights into the functional organization of the neural circuits in visual cortex-information that is essential for understanding the neural basis of visual perception and provides the foundation for evaluating disruptions of normal cortical function that are common in neurological and neuropsychiatric disorders.

Public Health Relevance

The proposed experiments will provide new insight into the functional organization of cortical circuits that is critical for addressing numerous visual, neurological, and psychiatric disorders that are grounded in cortical circuit dysfunction.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
Project #
Application #
Study Section
Central Visual Processing Study Section (CVP)
Program Officer
Steinmetz, Michael A
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Max Planck Florida Corporation
United States
Zip Code
Lee, Kuo-Sheng; Huang, Xiaoying; Fitzpatrick, David (2016) Topology of ON and OFF inputs in visual cortex enables an invariant columnar architecture. Nature 533:90-4
Huang, Xiaoying; Elyada, Yishai M; Bosking, William H et al. (2014) Optogenetic assessment of horizontal interactions in primary visual cortex. J Neurosci 34:4976-90
Van Hooser, Stephen D; Roy, Arani; Rhodes, Heather J et al. (2013) Transformation of receptive field properties from lateral geniculate nucleus to superficial V1 in the tree shrew. J Neurosci 33:11494-505
Meng, Yicong; Tanaka, Shigeru; Poon, Chi-Sang (2012) Comment on ""Universality in the evolution of orientation columns in the visual cortex"". Science 336:413; author reply 413
Johnson, Elizabeth N; Van Hooser, Stephen D; Fitzpatrick, David (2010) The representation of S-cone signals in primary visual cortex. J Neurosci 30:10337-50
Kaschube, Matthias; Schnabel, Michael; Lowel, Siegrid et al. (2010) Universality in the evolution of orientation columns in the visual cortex. Science 330:1113-6
MacEvoy, Sean P; Tucker, Thomas R; Fitzpatrick, David (2009) A precise form of divisive suppression supports population coding in the primary visual cortex. Nat Neurosci 12:637-45
Fitzpatrick, D; Usrey, W M; Schofield, B R et al. (1994) The sublaminar organization of corticogeniculate neurons in layer 6 of macaque striate cortex. Vis Neurosci 11:307-15
Muly, E C; Fitzpatrick, D (1992) The morphological basis for binocular and ON/OFF convergence in tree shrew striate cortex. J Neurosci 12:1319-34
Usrey, W M; Muly, E C; Fitzpatrick, D (1992) Lateral geniculate projections to the superficial layers of visual cortex in the tree shrew. J Comp Neurol 319:159-71

Showing the most recent 10 out of 14 publications