However, recall that the LGN is segregated by eye. This separation is maintained as the axons enter the cortex. As the signal is transmitted to upper layers of cortex, the information from the two eyes is mixed and binocular vision is created, but here in 4C the two eyes are still entirely separate. Therefore, if you could label the inputs from a single eye, in 4C you would see little pillars of label. These are the ocular dominance stripes.
Cytochrome oxidase is a staining technique which preferentially stains metabolically active neurons.
This is how one eye can be selectively stained, as in the picture to the right. However, researchers staining with cytochrome oxidase happened upon another property of V1. In layer 3, certain areas always seemed to stain darkly, regardless of the status of the eyes. Tangential sections through layer 3 showed a pattern similar to leopard spots. These areas of stain were named blobs , and the pale areas around them, interblobs .