GFR alpha 3, a component of the artemin receptor, is required for migration and survival of the superior cervical ganglion

GFR alpha 3 is a component of the receptor for the neurotrophic factor arte min. The role of GFR alpha 3 in nervous system development was examined by generating mice in which the Gfr alpha 3 gene was disrupted. The Gfr alpha 3(-/-) mice exhibited severe defects in the superior cervical ganglion (SCG ), whereas other ganglia appeared normal. SCG precursor cells in the mutant embryos failed to migrate to the correct position, and they subsequently f ailed to innervate the target organs. In wildtype embryos, Gfr alpha 3 was expressed in migrating SCG precursors, and artemin was expressed in and nea r the SCG. After birth, SCG neurons in the mutant mice underwent progressiv e cell death. These observations suggest that GFR alpha 3-mediated signalin g is required both for the rostral migration of SCG precursors and for the survival of mature SCG neurons.