Neurophilosophy reviews an interesting paper that traces the directional preferences of visual cortex neurons in developing ferrets:
Now researchers from Duke University Medical Center have observed how early visual experience drives maturation of the visual cortex. Using sophisticated in vivo imaging techniques, they have monitored the changes in the functional properties of visual cortical neurons which occur immediately following eye opening in ferrets. In this way, they show how the first stimuli to enter the eye lead to the emergence of direction selectivity in visually naïve neurons and to the organization of the cells into groups which respond to a preferred direction.
