Mapping vestibular and visual contributions to angular head velocity tuning in the cortex.

Area of Science:

• Neuroscience
• Systems Neuroscience
• Sensory Processing

Background:

• Neurons signaling angular head velocity (AHV) are vital for spatial and visual processing.
• Isolating sensory inputs and mapping cortical distribution of AHV cells has been challenging.

Purpose of the Study:

• To develop a method for studying AHV cells in awake, head-fixed mice.
• To investigate the sensory modalities driving AHV cells.
• To map the cortical distribution of AHV-signaling neurons.

Main Methods:

• Developed a novel two-photon microscopy technique for rotating awake, head-fixed mice in a visual environment.
• Recorded neuronal activity in various cortical areas, including retrosplenial cortex.
• Analyzed neuronal tuning properties in response to head movements and visual stimuli.

Main Results:

• Identified that 10% of neurons in layer 2/3 of the retrosplenial cortex signal AHV.
• AHV cell tuning is primarily driven by vestibular input, with visual input contributing at lower speeds.
• AHV cells were found in all explored cortical areas (motor, somatosensory, visual, posterior parietal cortex).
• Vestibular and visual contributions to AHV signaling varied significantly across different cortical areas.

Conclusions:

• Many cortical circuits receive angular head velocity (AHV) information.
• AHV provides a basis for integrating sensorimotor and cognitive information across the cortex.
• This study reveals the widespread presence and sensory integration properties of AHV cells in the brain.