Figure 6

Undulating band heterotopia; fetus of 23 weeks. a: A slice of the fixed brain shows large ventricle and a thin cortical mantle in which the undulating cortical neuronal band can just be made out (arrows). b: H&E stained section shows a festooned band of neurones sweeping from the brain surface (L) to the ventricular zone where germinal matrix (GM) separates it from the ventricular wall.