Relationships of Local Inhibitory and Excitatory Circuits to Orientation Preference Maps in Ferret Visual Cortex
- Resource Type
- Authors
- Birgit Roerig; B. Chen
- Source
- Cerebral Cortex. 12:187-198
- Subject
- Brain Mapping
Pyramidal Cells
Cognitive Neuroscience
Ferrets
Neural Inhibition
Biology
Visual system
Inhibitory postsynaptic potential
Brain mapping
Photostimulation
Cellular and Molecular Neuroscience
Visual cortex
medicine.anatomical_structure
Postsynaptic potential
Orientation
Synapses
medicine
Excitatory postsynaptic potential
Animals
Visual Pathways
Neuroscience
Photic Stimulation
Visual Cortex
- Language
- ISSN
- 1460-2199
1047-3211
The contribution and precise role of intracortical circuits in generating orientation tuned responses in visual cortical neurons is still controversial. To address this question, the relationship between excitatory and inhibitory synaptic connections and orientation maps in ferret striate cortex was investigated by combining in vivo optical imaging and in vitro scanning laser photostimulation. Excitatory and inhibitory inputs to pyramidal cells originated preferentially from regions with similar orientation preference. Prominent cross-orientation inhibition was not observed, arguing against cross-orientation models of orientation selectivity. The tuning of inhibitory inputs was significantly broader in both layer 2/3 and layer 5/6 pyramidal neurons compared to the tuning of excitatory inputs. Local excitatory inputs were more prominent in the 0-20 degrees tuning difference range between pre- and postsynaptic cells than inhibitory inputs, whereas inhibition dominated in the 20-40 degrees tuning difference range. These differences in tuning of excitatory and inhibitory inputs onto individual cells are consistent with the predictions of recurrent models of orientation selectivity.