Spontaneous Infra-slow Brain Activity Has Unique Spatiotemporal Dynamics and Laminar Structure

Area of Science:

• Neuroscience
• Systems Neuroscience
• Computational Neuroscience

Background:

• Spontaneous infra-slow activity (<0.1Hz) is studied in brain function using fMRI and optical imaging.
• The neurophysiological basis of infra-slow activity (ISA) remains unclear, questioning if it's a distinct process or slow analog of faster neural activity.

Purpose of the Study:

• To investigate the neurophysiological basis of infra-slow activity (ISA).
• To determine if ISA represents a distinct physiological process or a low-frequency component of faster neural activity.

Main Methods:

• Whole-cortex calcium/hemoglobin imaging in mice.
• Laminar electrophysiology in mice.
• Analysis of spatiotemporal trajectories and cross-laminar dynamics.

Main Results:

• Infra-slow activity (ISA) exhibits state-dependent spatiotemporal trajectories in the cortex, distinct from delta activity.
• ISA travels through specific cortical layers with unique cross-laminar temporal dynamics, differing from higher frequency local field potential activity.

Conclusions:

• Infra-slow activity (ISA) is a distinct neurophysiological process.
• The observed ISA dynamics are reflected in fMRI blood oxygen signals.