PRESYNAPTIC NETWORKS. Single-cell-initiated monosynaptic tracing reveals layer-specific cortical network modules
Adrian Wertz1, Stuart Trenholm1, Keisuke Yonehara1
1Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
Science (New York, N.Y.)
|July 4, 2015
Summary
Cortical networks exhibit distinct organization for processing visual motion. Some networks lock layer-specific modules to motion direction, while others show varied preferences across layers.
Area of Science:
- Neuroscience
- Systems Neuroscience
- Visual Cortex Research
Background:
- Individual neurons in the cortex display selectivity for environmental features like visual motion.
- The relationship between single-neuron selectivity and the organization of presynaptic networks across cortical layers is not well understood.
Purpose of the Study:
- To investigate the functional organization of presynaptic networks in the mouse primary visual cortex in response to visual motion.
- To determine if presynaptic network activity is consistently tuned to the preferred stimulus feature of the postsynaptic neuron.
Main Methods:
- Utilized single-cell-initiated, monosynaptically restricted retrograde transsynaptic tracing with rabies viruses.
- Employed GCaMP6s for in vivo imaging of visual motion-evoked activity in layer 2/3 pyramidal neurons and their presynaptic partners.
- Analyzed neuronal activity across different cortical layers in the primary visual cortex.
Main Results:
- Neurons within each cortical layer demonstrated similar motion direction preferences, forming distinct layer-specific functional modules.
- In approximately one-third of the analyzed networks, these layer modules were aligned with the direction preference of the postsynaptic neuron.
- In the remaining networks, the direction preference varied significantly across different cortical layers.
Conclusions:
- The primary visual cortex contains distinct types of cortical networks: feature-locked and feature-variant.
- These findings reveal diverse organizational principles within cortical circuits for sensory information processing.
