To understand cortical functions, it is essential to determine how information contained in sensory input is represented and processed in individual cortical neurons that are morphologically and neurochemically diverse. To understand mechanisms underlying the representational and processing properties of individual cortical neurons, a blind, in vivo, whole-cell patch-recording technique has been applied to examine sensory-driven excitatory and inhibitory synaptic inputs onto cortical neurons. Results from such studies have provided new insights into synaptic circuit mechanism underlying cortical neurons' response properties. Although this technique can be combined with post hoc histological methods to reconstruct the morphology of recorded cells, its blind nature largely limits its potential in examining various cell types in the cortex, since it normally results in a biased sampling of excitatory pyramidal neurons in the cortex. In this exploratory project, we will study a new technique for revealing functional properties and synaptic inputs of inhibitory cortical neurons in vivo, two-photon imaging guided patch recording (TPGP) in which fluorescently labeled neurons are visualized by two-photon imaging and specifically targeted for patch recording. This technique has benefited from recent development of mouse genetics in labeling cells of specific types with fluorescence proteins such as green fluorescence protein (GFP), with their expression controlled by cell-type specific promoters. At an initial step, we will apply this recording technique to GFP-labeled GABAergic interneurons in the supragranular layers (L1-3) of mouse primary visual cortex (V1), to address the receptive field properties of these neurons and how these properties are determined by the integration of visually activated excitatory and inhibitory synaptic inputs. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21EY018718-01
Application #
7360274
Study Section
Central Visual Processing Study Section (CVP)
Program Officer
Oberdorfer, Michael
Project Start
2007-12-01
Project End
2009-11-30
Budget Start
2007-12-01
Budget End
2008-11-30
Support Year
1
Fiscal Year
2008
Total Cost
$244,500
Indirect Cost
Name
University of Southern California
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Li, Ya-Tang; Ma, Wen-Pei; Pan, Chen-Jie et al. (2012) Broadening of cortical inhibition mediates developmental sharpening of orientation selectivity. J Neurosci 32:3981-91
Liu, Bao-hua; Li, Ya-tang; Ma, Wen-pei et al. (2011) Broad inhibition sharpens orientation selectivity by expanding input dynamic range in mouse simple cells. Neuron 71:542-54
Liu, Bao-hua; Li, Pingyang; Sun, Yujiao J et al. (2010) Intervening inhibition underlies simple-cell receptive field structure in visual cortex. Nat Neurosci 13:89-96
Ma, Wen-pei; Liu, Bao-hua; Li, Ya-tang et al. (2010) Visual representations by cortical somatostatin inhibitory neurons--selective but with weak and delayed responses. J Neurosci 30:14371-9
Sun, Yujiao J; Wu, Guangying K; Liu, Bao-Hua et al. (2010) Fine-tuning of pre-balanced excitation and inhibition during auditory cortical development. Nature 465:927-31
Wang, Sheng-Zhi; Liu, Bao-Hua; Tao, Huizhong W et al. (2009) A genetic strategy for stochastic gene activation with regulated sparseness (STARS). PLoS One 4:e4200
Liu, Bao-hua; Li, Pingyang; Li, Ya-tang et al. (2009) Visual receptive field structure of cortical inhibitory neurons revealed by two-photon imaging guided recording. J Neurosci 29:10520-32