Cortex-wide characterization of decision-making neural dynamics during spatial navigation.

Area of Science:

• Neuroscience
• Systems Neuroscience
• Cognitive Neuroscience

Background:

• Decision-making in freely moving animals involves complex interactions between cortical and subcortical brain regions.
• Understanding the spatiotemporal coordination of these regions during decision-making is crucial but remains incompletely understood.

Purpose of the Study:

• To investigate cortex-wide calcium dynamics during decision-making in mice navigating an 8-maze.
• To compare brain activity patterns between a task requiring working memory and a fixed-reward paradigm.

Main Methods:

• Utilized head-mounted widefield microscopy to record cortex-wide calcium dynamics in mice expressing GCaMP7f.
• Employed two behavioral paradigms: an alternating pattern requiring short-term memory and a left-side reward-only rule change.
• Identified and analyzed distinct cortex-wide activation states and their sequences (motifs).

Main Results:

• Cortical activation states differed significantly between the two paradigms.
• A visual/retrosplenial cortical state was more probable during the alternating (working memory) paradigm.
• A secondary motor and posterior parietal state was more probable during the left-only (fixed reward) paradigm.
• Identified three state sequences (motifs) showing anterior and posterior activity propagations.
• Anterior propagating motifs peaked around decision points, while posterior motifs peaked after decisions and were more frequent in the fixed reward paradigm.

Conclusions:

• The probabilities and sequences of cortical states vary depending on whether working memory is required or a fixed reward trajectory is used.
• Posterior propagating motifs, potentially reflecting internal feedback, are more prevalent in fixed reward scenarios, suggesting distinct neural mechanisms for different decision-making contexts.