Foci of orientation plasticity in visual cortex
1Department of Brain and Cognitive Sciences and Center for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. vdragoi@ai.mit.edu
Nature
|May 3, 2001
Summary
Neurons in the cat visual cortex (V1) exhibit localized, short-term plasticity in orientation tuning. Pinwheel centers show significant adaptation, unlike surrounding areas, suggesting non-uniform cortical plasticity.
Area of Science:
- Neuroscience
- Visual Cortex Plasticity
- Cortical Microcircuits
Background:
- Cortical areas are typically considered uniform in their plasticity.
- Neurons in the visual cortex are organized into orientation-tuned domains and pinwheel centers.
Purpose of the Study:
- To investigate the spatial uniformity of adaptation-induced plasticity in the cat striate cortex (V1).
- To determine if neurons in different cortical domains (iso-orientation vs. pinwheel centers) exhibit differential plasticity.
Main Methods:
- Electrophysiological recordings from cat V1 neurons.
- Adaptation using oriented drifting grating stimuli.
- Analysis of orientation tuning properties before and after adaptation.
Main Results:
- Neurons at and near V1 pinwheel centers showed significant, adaptation-induced plasticity in orientation tuning.
- Adaptation caused repulsive shifts in orientation preference and altered response magnitudes in pinwheel center neurons.
- Neurons in iso-orientation domains exhibited minimal changes in tuning after adaptation.
Conclusions:
- Cortical plasticity, specifically orientation tuning adaptation, is not uniform across V1.
- Pinwheel centers represent foci of pronounced short-term plasticity, differing from iso-orientation domains.
- Local intracortical interactions likely mediate the observed anisotropy in adaptation-induced plasticity.
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