 |
||||
|
||||
|
||||
|
||||
The Journal of Neuroscience, September 19, 2007, 27(38):10299-10310; doi:10.1523/JNEUROSCI.2257-07.2007
Previous Article | Next Article
Behavioral/Systems/Cognitive
Alteration of Visual Input Results in a Coordinated Reorganization of Multiple Visual Cortex Maps
Brandon J. Farley,1 Hongbo Yu,1 Dezhe Z. Jin,2 andMriganka Sur1 1Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and 2Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802
Correspondence should be addressed to Mriganka Sur, Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 46, Room 6237, Cambridge, MA 02139. Email: msur{at}mit.edu
In the adult visual cortex, multiple feature maps exist and have characteristic spatial relationships with one another. The relationships can be reproduced by "dimension-reduction" computational models, suggesting that the principles of continuity and coverage may underlie cortical map organization. However, the mechanisms responsible for establishing these relationships are unknown. We explored whether removing one feature map during development causes a coordinated reorganization of the remaining maps or whether the remaining maps are unaffected. We removed the ocular dominance map by monocular enucleation in newborn ferrets, so that single eye stimulation drove the cortex in a more spatially uniform manner in adult monocular animals compared with normal animals. Maps of orientation, spatial frequency, and retinotopy formed in monocular ferrets, but their structures and spatial relationships differed from those in normal ferrets. The wavelength of the orientation map increased, so that the average orientation gradient across the cortex decreased. The decrease in the orientation gradient in monocular animals was most prominent in the high gradient regions of the spatial frequency map, indicating a coordinated reorganization between these two maps. In monocular animals, the orthogonal relationship between the orientation and spatial frequency maps was preserved, and the orthogonal relationship between the orientation and retinotopic maps became more pronounced. These results were consistent with detailed predictions of a dimension-reduction model of cortical organization. Thus, the number of feature maps in a cortical area influences the relationships between them, and inputs to the cortex have a significant role in generating these relationships.
Key words: development; orientation; ocular dominance; spatial frequency; retinotopy; dimension-reduction
Received May 17, 2007; revised July 16, 2007; accepted Aug. 3, 2007.
Correspondence should be addressed to Mriganka Sur, Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 46, Room 6237, Cambridge, MA 02139. Email: msur{at}mit.edu
Related articles in J. Neurosci.:
- This Week in The Journal
J. Neurosci. 2007 27: i.[Full Text]
This article has been cited by other articles:
N. P. Issa, A. Rosenberg, and T. R. Husson
Models and Measurements of Functional Maps in V1
J Neurophysiol, June 1, 2008; 99(6): 2745 - 2754.
[Abstract] [Full Text] [PDF]
|
|
|
|
 |
|