Arousal and locomotion make distinct contributions to cortical activity patterns and visual encoding

Area of Science:

• Neuroscience
• Cortical circuits
• Brain states

Background:

• Cortical activity is state-dependent, but transitions between waking states are poorly understood.
• Distinct patterns exist between quiescence and locomotion in mouse V1, potentially due to motor feedback or arousal.
• Pupil diameter is a reliable indicator of arousal levels.

Purpose of the Study:

• To investigate the distinct roles of arousal and locomotion in shaping cortical activity during state transitions.
• To dissociate the effects of arousal and locomotion on neural activity in mouse V1.
• To understand how these factors contribute to functional flexibility in the cortex.

Main Methods:

• Recorded single cells and local field potentials from mouse V1.
• Utilized head-fixed mice on a running wheel to control locomotion.
• Monitored pupil diameter to quantify arousal levels.
• Analyzed naturally occurring and induced state transitions.

Main Results:

• Arousal suppressed spontaneous neuronal firing and altered population activity temporal patterns.
• Increased arousal enhanced the signal-to-noise ratio of visual responses and reduced noise correlations.
• Locomotion, not arousal, was responsible for increased firing during movement.
• Dissociated arousal and locomotion effects in V1.

Conclusions:

• Arousal and locomotion play complementary roles in cortical functional flexibility.
• Arousal modulates spontaneous activity and sensory processing efficiency.
• Locomotion specifically influences movement-related neural activity.
• Understanding these distinct roles is crucial for comprehending brain state dynamics.