Recent receptive field mapping studies of primary somatosensory cortex (SI) in cat and monkey have demonstrated that the body surface is represented as a mosaic of discrete placed-defined cortical columns, """"""""segregates"""""""", approximately 0.3-0.6 mm in diameter. The neuroanatomy of these cortical modules will be studied in cats and rats: Small injections of retrograde tracers, including gold-labeled wheat germ agglutinin conjugated to apo- horseradish peroxidase (WGA-apoHRP-Au) and various fluorescent tracers, will be made in individual physiologically-identified SI segregates to establish their thalamic input. Similar experiments will be performed using neurotropic viral tracers to permit transsynaptic retrograde labeling. In this way, the disynaptic pathways to the cortex from the dorsal column nuclei and the spinal dorsal horn will be studied. The organization of inhibitory intracortical connections of electrophysiologically-defined segregates will be studied using the transmitter-selective retrograde tracer [3H]GABA, and by combining GABA immunocytochemistry with WGA-apoHRP-Au pathway tracing. Retrograde transport of the transmitter-selective tracer [3H]D-aspartate will be used to study the organization of excitatory intracortical connections; immunocytochemistry with antibodies for glutamate and aspartate will be used to further define the transmitter used by these neurons. This analysis of the modular connectivity of SI directly addresses fundamental principles of cortical organization.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS029879-02
Application #
3416809
Study Section
Sensory Disorders and Language Study Section (CMS)
Project Start
1991-07-20
Project End
1995-06-30
Budget Start
1992-07-01
Budget End
1993-06-30
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Valtschanoff, J G; Weinberg, R J (2001) Laminar organization of the NMDA receptor complex within the postsynaptic density. J Neurosci 21:1211-7
Valtschanoff, J G; Burette, A; Davare, M A et al. (2000) SAP97 concentrates at the postsynaptic density in cerebral cortex. Eur J Neurosci 12:3605-14
Naisbitt, S; Valtschanoff, J; Allison, D W et al. (2000) Interaction of the postsynaptic density-95/guanylate kinase domain-associated protein complex with a light chain of myosin-V and dynein. J Neurosci 20:4524-34
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Valtschanoff, J G; Burette, A; Wenthold, R J et al. (1999) Expression of NR2 receptor subunit in rat somatic sensory cortex: synaptic distribution and colocalization with NR1 and PSD-95. J Comp Neurol 410:599-611
Kharazia, V N; Weinberg, R J (1999) Immunogold localization of AMPA and NMDA receptors in somatic sensory cortex of albino rat. J Comp Neurol 412:292-302
Conti, F; Weinberg, R J (1999) Shaping excitation at glutamatergic synapses. Trends Neurosci 22:451-8
Niethammer, M; Valtschanoff, J G; Kapoor, T M et al. (1998) CRIPT, a novel postsynaptic protein that binds to the third PDZ domain of PSD-95/SAP90. Neuron 20:693-707
Hsueh, Y P; Yang, F C; Kharazia, V et al. (1998) Direct interaction of CASK/LIN-2 and syndecan heparan sulfate proteoglycan and their overlapping distribution in neuronal synapses. J Cell Biol 142:139-51
Srivastava, S; Osten, P; Vilim, F S et al. (1998) Novel anchorage of GluR2/3 to the postsynaptic density by the AMPA receptor-binding protein ABP. Neuron 21:581-91

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