The Distribution and Morphology of Calbindin D28K- and Calretinin-immunoreactive Neurons in the Visual Cortex of Mouse

We studied the distribution and morphology of calbindin D28K- and calretinin-immunoreactive (IR) neurons in the mouse visual cortex with immunocytochemistry. Most of the calbindin D28K-IR neurons were located in layers II/III and V, while calretinin-IR neurons were predominantly located in layers II/III. The labeled neurons showed variations in morphology. The majority of the calbindin D28K-IR neurons were stellate and round or oval cells with multipolar dendrites. The majority of calretinin-IR neurons were vertical fusiform cells with long processes traveling perpendicular to the pial surface. In the mouse visual cortex, 20.2% of calbindin D28K-IR neurons contained calretinin and 27.2% of calretinin-IR neurons contained calbindin D28K. These results indicate that the calcium-binding proteins, calbindin D28K and calretinin are distributed in specific layers and in selective cell types of the mouse visual cortex.