We will study the mechanisms by which visual information is transformed in the pathway from retina, to the lateral geniculate nucleus of the thalamus (LGN), and finally to layer 4 of primary visual cortex. The physiology of these three populations of neurons in the visual system have been extensively studied over the past forty years. Individual connections between these neurons have also been studied. Until recently, however, there has not been an explicit exploration of the interactions between multiple convergent inputs to single cells, or of the divergent projection from single cells to their multiple targets. The proposal is divided into three broad sections whose overarching goal is to understand the integration of multiple inputs to visual cortical neurons. In the first (A), we will study this problem directly by recording simultaneously in the LGN and layer 4 of visual cortex. In particular, we will concentrate on exploring synergistic interactions between near- synchronous inputs from convergent thalamic afferents. In the second section (B), we will study how the correlational structure of the thalamic inputs to visual cortex are determined by their retinal inputs. Preliminary results indicate that there is strong synchrony between groups of neurons in the thalamus. By recording simultaneously from neurons in the retina and LGN, we will study how synchrony in the LGN is caused by divergent input from the retina. Finally, in the third section (C), we will record simultaneously from all three levels in the pathway: retina, LGN, and visual cortex. This study will help us assess quantitatively the importance of the effects studied in (A) and (B) on the transmission of visual information from retina to cortex: single retinal ganglion cells diverge to synchronize to small pools of thalamic neurons, these synchronized neurons re-converge in a synergistic manner onto single cortical neurons. This basic research on information processing in the visual cortex should further our knowledge of general mechanisms of cortical function. Only by exploring the detailed interplay of multiple thalamic inputs to cortical neurons can we begin to understand functional disorders of this pathway, such as in certain forms of epilepsy.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY010115-09
Application #
6179805
Study Section
Visual Sciences B Study Section (VISB)
Program Officer
Oberdorfer, Michael
Project Start
1993-04-01
Project End
2002-03-31
Budget Start
2000-04-01
Budget End
2001-03-31
Support Year
9
Fiscal Year
2000
Total Cost
$348,096
Indirect Cost
Name
Harvard University
Department
Biology
Type
Schools of Medicine
DUNS #
082359691
City
Boston
State
MA
Country
United States
Zip Code
02115
Lee, Wei-Chung Allen; Bonin, Vincent; Reed, Michael et al. (2016) Anatomy and function of an excitatory network in the visual cortex. Nature 532:370-4
Glickfeld, Lindsey L; Andermann, Mark L; Bonin, Vincent et al. (2013) Cortico-cortical projections in mouse visual cortex are functionally target specific. Nat Neurosci 16:219-26
Andermann, Mark L; Gilfoy, Nathan B; Goldey, Glenn J et al. (2013) Chronic cellular imaging of entire cortical columns in awake mice using microprisms. Neuron 80:900-13
Reid, R Clay (2012) From functional architecture to functional connectomics. Neuron 75:209-17
Bock, Davi D; Lee, Wei-Chung Allen; Kerlin, Aaron M et al. (2011) Network anatomy and in vivo physiology of visual cortical neurons. Nature 471:177-82
Lee, Wei-Chung Allen; Reid, R Clay (2011) Specificity and randomness: structure-function relationships in neural circuits. Curr Opin Neurobiol 21:801-7
Bonin, Vincent; Histed, Mark H; Yurgenson, Sergey et al. (2011) Local diversity and fine-scale organization of receptive fields in mouse visual cortex. J Neurosci 31:18506-21
Kleinfeld, David; Bharioke, Arjun; Blinder, Pablo et al. (2011) Large-scale automated histology in the pursuit of connectomes. J Neurosci 31:16125-38
Histed, Mark H; Bonin, Vincent; Reid, R Clay (2009) Direct activation of sparse, distributed populations of cortical neurons by electrical microstimulation. Neuron 63:508-22
Ohki, Kenichi; Reid, R Clay (2007) Specificity and randomness in the visual cortex. Curr Opin Neurobiol 17:401-7

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