Interdigitating Modules for Visual Processing During Locomotion and Rest in Mouse V1

Area of Science:

• Neuroscience
• Visual System Processing
• Cortical Circuits

Background:

• Layer 1 of the primary visual cortex (V1) receives locomotion-related signals from the dorsal lateral geniculate (dLGN) and lateral posterior (LP) thalamic nuclei.
• These inputs target distinct regions within V1 Layer 1: dLGN to M2+ patches and LP to M2- interpatches, indicating segregated motion processing networks.

Purpose of the Study:

• To investigate differential activation of L2/3 neurons in V1 by locomotion under M2+ and M2- modules.
• To explore the role of feedback connections from higher cortical areas to V1 Layer 1 in modulating these responses.

Main Methods:

• Calcium imaging in head-fixed awake mice to monitor neuronal activity.
• Pathway tracing to identify feedback connections from cortical areas to V1.
• Analysis of neuronal activity modulation by locomotion and correlated variability.

Main Results:

• Locomotion strongly modulated cell clusters aligned with M2- interpatches, while M2+ patches showed weak modulation.
• M2- interpatch cells exhibited increased correlated variability across distant visual field sites, suggesting broader integration.
• Pathway tracing revealed looped, like-to-like networks involving MOs-, PM-, and RSP-projecting neurons and feedback to V1 Layer 1.

Conclusions:

• Distinct V1 Layer 1 networks process locomotion-related signals, with M2- interpatches showing stronger modulation and wider integration.
• Feedback connections from higher cortical areas and somatostatin (SST) interneurons likely shape these locomotion-modulated subnetworks within M2- interpatches.