Mapping Functional Connectivity from the Dorsal Cortex to the Thalamus.

Area of Science:

• Neuroscience
• Systems Neuroscience
• Computational Neuroscience

Background:

• The corticothalamic network is vital for cognitive functions like sensation, memory, decision-making, and action execution.
• A comprehensive understanding of corticothalamic functional connectivity remains elusive.
• Systematic mapping of these connections is essential for deciphering brain function.

Purpose of the Study:

• To systematically map functional connections from the dorsal cortex to the thalamus in awake mice.
• To develop a high-throughput method for characterizing corticothalamic circuitry.
• To investigate the dynamics and organization of corticothalamic excitatory inputs.

Main Methods:

• Developed a high-throughput method combining optogenetic inactivation with multi-channel electrophysiological recordings in awake mice.
• Systematically inactivated specific cortical regions to observe effects on thalamic neuronal activity.
• Utilized cluster analysis to identify distinct neuronal dynamics within thalamic nuclei.

Main Results:

• Cortical inactivation rapidly reduced thalamic activity, revealing topographically organized corticothalamic excitatory inputs.
• Neuronal groups within thalamic nuclei exhibited distinct activity dynamics, which evolved over time and were modulated by behavioral states.
• Identified a subset of thalamic neurons receiving convergent inputs from widespread cortical regions.

Conclusions:

• Presented a novel framework for analyzing large electrophysiological datasets with region-specific optogenetic perturbations.
• Established a foundational understanding of corticothalamic functional connectivity and information processing.
• The findings pave the way for further investigations into the complex corticothalamic pathway.