Decelerated migration of neocortical neurones in explant culture after exposure to radiation.

We describe a newly devised explant culture system employing rat neocortex in which neurones migrate in a fashion similar to that seen in vivo. Using neocortical explant culture we have demonstrated an effect of ionizing radiation on neuronal migration at doses as low as 10 cGy together with a changing pattern of expression of the neural cell adhesion molecule N-CAM. After a dose of more than 10 cGy there was a significant reduction in N-CAM immunoreactivity in the matrix cell zone. We do not know the reason why the reduction in N-CAM immunoreactivity is so localized, although it is not unlikely that the most active site in terms of N-CAM synthesis is significantly affected by radiation.