The primary visual cortex in the mouse: receptive field properties and functional organization

Area of Science:

• Neuroscience
• Visual System Research
• Cortical Organization

Background:

• Primary visual cortex (V1) processing is fundamental to visual perception.
• Understanding receptive field (RF) properties clarifies neuronal function.
• Mouse models offer insights into mammalian visual system organization.

Purpose of the Study:

• Characterize receptive field (RF) properties of mouse primary visual cortex (V1) neurons.
• Investigate the functional organization of V1 along radial and tangential dimensions.
• Analyze ocular dominance and binocular integration in the mouse striate cortex.

Main Methods:

• Single-unit recordings in C57B16 mouse primary visual cortex.
• Classification of neurons based on responses to oriented, moving, and stationary stimuli.
• Analysis of RF characteristics across cortical layers and dimensions.

Main Results:

• Identified orientation-selective (simple/complex, unidirectional) and non-oriented cells, with specific layer distributions (II-III for oriented, supra-/infra-granular for non-oriented asymmetric).
• Symmetric units (ON, OFF, ON/OFF) were predominantly found in layer IV.
• Layer IV showed the highest proportion of small RFs; binocular integration was substantial (70%), with contralateral eye dominance (95%).

Conclusions:

• Mouse V1 exhibits diverse neuronal functional types with distinct laminar and tangential organization.
• Layer IV is crucial for non-oriented and symmetric unit processing.
• Significant binocular integration occurs in the mouse striate cortex, with a strong contralateral eye influence.