The primary visual cortex contains how many horizontal layers?

The primary visual cortex contains how many horizontal layers?

• A. 4
• B. 6
• C. 8
• D. 10

Answer: (B)

The primary visual cortex, V1, has six horizontal layers organized from the pial surface to deeper tissue. This six-layer pattern, labeled I to VI, is a hallmark of the neocortex. Layer IV is the main entry point for input from the LGN, with sublayers 4A, 4B, 4Cα, and 4Cβ often described, while layers II/III handle corticocortical communication and layers V/VI project to subcortical targets and provide feedback. That combination of inputs, processing, and outputs conforms to six distinct laminae, so six is the correct count. Fewer or more layers do not match the standard lamination of V1.

The primary visual cortex, V1, has six horizontal layers organized from the pial surface to deeper tissue. This six-layer pattern, labeled I to VI, is a hallmark of the neocortex. Layer IV is the main entry point for input from the LGN, with sublayers 4A, 4B, 4Cα, and 4Cβ often described, while layers II/III handle corticocortical communication and layers V/VI project to subcortical targets and provide feedback. That combination of inputs, processing, and outputs conforms to six distinct laminae, so six is the correct count. Fewer or more layers do not match the standard lamination of V1.