In primates area Vl serves as the gate through which visual information reaches the rest of the cerebral cortex, influencing the conscious behavior of the animal. Adjacent area V2 receives parallel inputs from each of the Vl efferent cortico-cortical projection channels and retransmits each channel to more distant specialized cortical association areas. The studies proposed explore anatomical and physiological aspects of the internal circuitry of areas Vl, V2, and the more distant area V4. The long-term objectives are to arrive at a clearer understanding of the interactions of different channels of visual information within these areas, the pattern of information flow between them, and the nature of internal controls on their efferent projections.
The specific aims are: 1) Anatomical analysis of intrinsic pattern of connections in visual areas Vl, V2 and V4 to determine the extent of links made between different visual channels and the patterns of intrinsic organization characterizing each area. Techniques include analysis of Golgi preparations, and use of biocytin and HRP tracer substances. 2) Physiological exploration of area V2 to examine the transformation of properties between afferents and postsynaptic neurons and the role of intrinsic lateral connections in shaping V2 neuron response properties. Techniques include kainic acid destruction of postsynaptic neurons and unit recording with use of pharmacological block of intraareal connections. 3) Anatomical investigation of key local circuit neurons controlling efferent neuron activity in Vl, V2 and V4. Techniques include electronmicroscopy, Golgi preparations, and immunocytochemistry. 4) Exploration of the CFos gene product as a label for cells and circuits active in Vl, V2 and V4 under different conditions of visual stimulation. Immunocytochemical techniques will be used. These studies use the visual cortical areas of the primate as a model for understanding the functions of local circuits and association pathways in cerebral cortex. This understanding is essential for progress in determining the courses and appropriate treatments for cortical malfunctions in man, both in vision and in diseases such as Alzheimer's, schizophrenia, and other dementias.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY010021-02
Application #
3267299
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1992-08-01
Project End
1995-07-31
Budget Start
1993-08-01
Budget End
1994-07-31
Support Year
2
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of London Institute of Ophthalmlgy
Department
Type
DUNS #
City
London
State
Country
United Kingdom
Zip Code
Diederen, Roselie M H; Starnes, Catherine A; Berkowitz, Bruce A et al. (2006) Reexamining the hyperglycemic pseudohypoxia hypothesis of diabetic oculopathy. Invest Ophthalmol Vis Sci 47:2726-31
Bauer, U; Scholz, M; Levitt, J B et al. (1999) A model for the depth-dependence of receptive field size and contrast sensitivity of cells in layer 4C of macaque striate cortex. Vision Res 39:613-29
Lund, J S; Wu, C Q (1997) Local circuit neurons of macaque monkey striate cortex: IV. Neurons of laminae 1-3A. J Comp Neurol 384:109-26
Gegenfurtner, K R; Kiper, D C; Levitt, J B (1997) Functional properties of neurons in macaque area V3. J Neurophysiol 77:1906-23
Levitt, J B; Lund, J S; Yoshioka, T (1996) Anatomical substrates for early stages in cortical processing of visual information in the macaque monkey. Behav Brain Res 76:5-19
Yoshioka, T; Blasdel, G G; Levitt, J B et al. (1996) Relation between patterns of intrinsic lateral connectivity, ocular dominance, and cytochrome oxidase-reactive regions in macaque monkey striate cortex. Cereb Cortex 6:297-310
Levitt, J B; Yoshioka, T; Lund, J S (1995) Connections between the pulvinar complex and cytochrome oxidase-defined compartments in visual area V2 of macaque monkey. Exp Brain Res 104:419-30
Lund, J S; Wu, Q; Hadingham, P T et al. (1995) Cells and circuits contributing to functional properties in area V1 of macaque monkey cerebral cortex: bases for neuroanatomically realistic models. J Anat 187 ( Pt 3):563-81
Yoshioka, T; Levitt, J B; Lund, J S (1994) Independence and merger of thalamocortical channels within macaque monkey primary visual cortex: anatomy of interlaminar projections. Vis Neurosci 11:467-89
Levitt, J B; Yoshioka, T; Lund, J S (1994) Intrinsic cortical connections in macaque visual area V2: evidence for interaction between different functional streams. J Comp Neurol 342:551-70

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