Single-Cell Perturbations Reveal Selective Modulation of Causal Connectivity During Decision-Making

Area of Science:

• Neuroscience
• Systems Neuroscience
• Computational Neuroscience

Background:

• Decision-making involves sequential computations like evidence accumulation and motor output.
• Understanding how fixed neural circuits support these dynamic phases is a key challenge.
• Cortical connectivity modulation is a potential, yet untested, mechanism.

Purpose of the Study:

• To investigate whether neuronal connectivity in the retrosplenial cortex changes across different phases of a navigation-based decision-making task.
• To determine if these connectivity changes are specific to task engagement and behavioral epochs.

Main Methods:

• Utilized an all-optical method to probe causal connectivity.
• Focused on excitatory neurons in layer 2/3 of the mouse retrosplenial cortex.
• Compared neuronal connectivity during task performance versus a no-task baseline.

Main Results:

• Cortical connectivity during the task differed significantly from the no-task condition.
• Connectivity differences were most pronounced during the cue/decision phase.
• These task-related connectivity modulations diminished in later stages of the task.

Conclusions:

• Fast modulation of neuronal connectivity is a key mechanism supporting dynamic computations in neural circuits.
• The retrosplenial cortex exhibits experience-dependent connectivity changes during decision-making.
• This highlights the adaptability of neural circuits beyond fixed anatomical connections.