Thalamocortical interactions shape hierarchical neural variability during stimulus perception

Area of Science:

• Neuroscience
• Systems Neuroscience
• Sensory Processing

Background:

• The brain's hierarchical organization is crucial for sensory signal processing.
• Understanding functional connectivity's role in this hierarchy is key.

Purpose of the Study:

• Investigate hierarchical functional roles in the thalamocortical network.
• Examine neural variability and connectivity during vibrotactile stimulus detection.

Main Methods:

• Simultaneous neural recordings in monkeys performing a tactile detection task.
• Quantification of neural variability and directed functional connectivity.
• Analysis of neuronal dynamics across VPL, area 3b, and area 1.

Main Results:

• VPL and area 3b showed fast dynamics; area 1 exhibited slower timescales before stimulus onset.
• Inter-trial neural variability increased along the VPL-3b-1 network during stimulus presence.
• VPL established feedforward pathways to areas 3b and 1, regulating them via lower variability.
• Area 1's intrinsic timescales predicted intra-cortical interactions.

Conclusions:

• The thalamocortical network demonstrates hierarchical functional roles.
• Feedforward pathways and intrinsic timescales differentially contribute to sensory processing hierarchy.