A SEM study on the development of the ventricular surface morphology in the diencephalon of the rat

The morphogenesis of the ventricular surface of the diencephalon of the rat was studied using scanning electron microscopy, cryostat serial sections and direct observations under a dissection microscope. Based on these observations a description is given of the neuromeres present within the prosencephalon and of the termination of the sulcus limitans. Two conclusions are reached. First, three neuromeres are present in the prosencephalon. Neuromere I consists of the telencephalon, the hypothalamic regions and the parencephalon anterius. Neuromere II is the parencephalon posterius, neuromere III the synencephalon. Second, the sulcus limitans terminates ventrally in the parencephalon posterius and does not continue towards the preoptic recess. No exact termination point of the sulcus limitans could be delineated.