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Published on: January 10, 2019
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Disruption of Transthalamic Circuitry from the Primary Visual Cortex Impairs Visual Discrimination in Mice.
C McKinnon1, C Mo2,3, S M Sherman4
1Committee on Computational Neuroscience, University of Chicago, Chicago, Illinois 60637.
Summary
Inhibiting transthalamic circuits from the primary visual cortex (V1) impaired mice
Area of Science:
- Neuroscience
- Visual System
- Cortical Circuits
Background:
- Cortico-thalamo-cortical (transthalamic) circuits, originating from Layer 5 (L5) of the cortex, provide parallel communication routes between cortical areas.
- The precise role of these transthalamic circuits in perception and behavior has remained largely undetermined.
- Understanding these pathways is crucial for deciphering how sensory information is processed hierarchically to support perceptual decision-making.
Purpose of the Study:
- To investigate the causal role of L5-initiated transthalamic circuits in visual discrimination performance.
- To determine if selective inhibition of the primary visual cortex (V1) to pulvinar pathway impacts visual perception.
Main Methods:
- Targeted optogenetic inhibition of L5 corticothalamic terminals in the pulvinar of mice performing a visual discrimination task.
- Selective suppression of transthalamic circuits originating from V1.
- Assessment of behavioral performance across different visual stimulus orientations.
Main Results:
- Suppression of V1 transthalamic circuits significantly impaired visual discrimination performance.
- The behavioral deficits were retinotopically specific to the inhibited V1 region.
- This demonstrates a causal link between transthalamic pathway activity and visual perception.
Conclusions:
- L5-initiated transthalamic circuits are critical for accurate visual discrimination.
- These findings underscore the importance of including transthalamic pathways in models of cortical processing and perceptual decision-making.
- This study provides causal evidence for the role of visual transthalamic circuitry in behavior.
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