Cell production gradients in the developing ferret isocortex.

The accumulation of cells within the cortical plate was studied in ferrets at two developmental ages. A survey method based on the presumed radial organisation of cortical neuron production was used to sample variations in cell production along the rostrocaudal and laterodorsal axes of the brain. The resulting cell counts confirmed the presence of a gradient of cortical plate formation, with a rostrolateral focus. These findings were discussed in relation to some recent teratological studies on brain development in ferrets, where there has been a lack of normative data.