Which layers of the primary visual cortex receive thalamic input?

Which layers of the primary visual cortex receive thalamic input?

• A. Layer II/III
• B. Layer IV
• C. Layer V
• D. Layer VI

Answer: (B)

The primary visual cortex receives thalamic input at its cortical input layer, layer IV. The LGN sends its feedforward projections mainly to layer IV (especially sublayer 4C), delivering the raw visual signal directly to cortex. From this layer, the information is then passed to the superficial layers II/III for further processing and to deeper layers for various outputs. The other layers are more involved in processing or sending signals to subcortical targets or providing feedback to the thalamus, rather than serving as the main entry point for thalamic afferents. So, layer IV is the essential recipient of thalamic input.

The primary visual cortex receives thalamic input at its cortical input layer, layer IV. The LGN sends its feedforward projections mainly to layer IV (especially sublayer 4C), delivering the raw visual signal directly to cortex. From this layer, the information is then passed to the superficial layers II/III for further processing and to deeper layers for various outputs. The other layers are more involved in processing or sending signals to subcortical targets or providing feedback to the thalamus, rather than serving as the main entry point for thalamic afferents. So, layer IV is the essential recipient of thalamic input.