Functional development of direction and orientation selectivity in the mouse visual cortex
Madoka Narushima1,2., Nathalie L. Rochefort1, Christine Grienberger1, Nima Marandi1 and Arthur Konnerth1.
1Institut für Neurowissenschaften, Technische Universität München, Germany; 2Dept. Physiol., Tokyo Women’s Medical Univ.
In many species including carnivores such as cats and ferrets, direction and orientation selective neurons in the visual cortex are organized in columnar structure. Rodents lack such an anatomical feature, instead, orientation and direction selective neurons are distributed in a mixed salt-and-pepper manner. Here we report that in addition to their structure, developmental process of selectivity is different in mice and ferrets. It has been reported that development of direction selectivity requires visual experience in ferrets. We used two-photon calcium imaging of the layer 2/3 mouse visual cortex to study the development of direction and orientation selectivity at the level of single neurons in vivo. Surprisingly, we found that direction-selectivity developed normally in dark-reared mice, indicating that innate factors and not visual experience determine this early development. We found further that at eye opening the vast majority of orientation-selective neurons were also selective for the direction of stimulus motion. A comparison with previous results revealed striking functional similarities between cortical neurons and direction-selective ganglion cells in the mouse retina. Thus, combined with previous results, our findings suggest a new blueprint for the development of the mammalian visual system in which direction selectivity is present at eye-opening and develops normally in the absence of visual experience.