Across a variety of sensory systems, the cerebral cortex is known to be capable of responding to sensory loss with immediate reorganization of single neuron responses and functional maps. The rapid time course of these initial changes suggest prompt alterations in the properties of existing synaptic connections, though the circuit location and molecular mechanism of this form of rapid plasticity remains unknown. The current proposal hypothesizes that the first changes in circuit plasticity associated with sensory loss and diminished feedforward drive occur in layer 2/3, and involve a homeostatic upregulation of existing horizontal connections, many of which are long-range projections that confer response properties from other cortical columns onto affected neurons. This hypothesis makes specific predictions for what changes in single neuron response properties and feature maps should ensue upon focal modulation of feedforward drive, and presents a method for systematically and reversibly modulating this drive experimentally. The hypothesis also suggests that specific changes in the function of existing synapses should underlie observed changes in feature maps, and provides an in vitro framework by which to characterize these synaptic changes. Understanding the locus, mechanisms and dynamics of these first plastic changes associated with dramatic shifts in input drive will provide crucial insight into the possibility of utilizing intracortical network features to facilitate sensorv processing in the face of sensorv loss. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32EY017500-01
Application #
7113394
Study Section
Special Emphasis Panel (ZRG1-F02B-B (20))
Program Officer
Oberdorfer, Michael
Project Start
2006-03-04
Project End
2009-03-03
Budget Start
2006-03-04
Budget End
2007-03-03
Support Year
1
Fiscal Year
2006
Total Cost
$43,966
Indirect Cost
Name
Massachusetts Institute of Technology
Department
Miscellaneous
Type
Other Domestic Higher Education
DUNS #
001425594
City
Cambridge
State
MA
Country
United States
Zip Code
02139
Tropea, Daniela; Giacometti, Emanuela; Wilson, Nathan R et al. (2009) Partial reversal of Rett Syndrome-like symptoms in MeCP2 mutant mice. Proc Natl Acad Sci U S A 106:2029-34