This project will examine the development of electrophysiological properties in neural-lineage cells of the early Xenopus embryo. Although much attention has focussed on the modulation of populations of ion channels during the terminal differentiation of specific sets of post-mitotic neurons, very little information is available about the development of ion channel populations in neural-lineage cells at earlier stages, when initial commitment to neural phenotypes occurs. Dr. Moody will use patch clamp techniques to study this problem in the Xenopus embryo, at stages between the unfertilized oocyte and the neurula. He will examine the stages at which cells involved in the formation of the embryonic nervous system first express functional ion channel populations distinct from cells of other fates, and then investigate the developmental processes by which the electrical properties of the oocyte are transformed into those of cells committed to neuronal phenotypes. Particular attention will be paid to the roles of ion channel synthesis, the modulation of pre-existing channels, and the spatial distribution of ion channels over the surface of single cells in the early electrophysiological differentiation of the nervous system.
