Physiological Gradients of Voltage as Controls of Neural Morphogenesis
It has long been suspected that endogenous steady ionic currents and natural voltage gradients may play a role in the early development of animals and plants9,10,13,15. For example, the cytoplasmic localizations in germinating fucus eggs may be controlled by a steady transcellular calcium current11,18, and a steady outwardly directed ionic current predicts the exact locus of limb development in both frog and salamander embryos4,5,19.Transcellular currents also play a critical role in cell and tissue reactions to injury and in their subsequent regeneration1,3,14. These experiments also provide insights into the use of imposed voltage gradients as a clinical treatment for nervous system trauma3. More recently, new studies provide direct evidence for a controlling role of endogenous currents and voltages in vertebrate morphogenesis, particularly when we restrict our attention to the early nervous system.
KeywordsIonic Current Neural Plate Xenopus Embryo Voltage Gradient Limb Development
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