GDNF, RET and GFR alpha-1-3 mRNA expression in the developing human spinalcord and ganglia

THE identification of endogenous neurotrophic factors and their receptors i n human spinal cord is important not only to understand development, but al so in the consideration of possible future therapies for neurodegenerative disorders and trauma. Using in situ hybridization, the expression of glial cell line-derived neurotrophic factor (GDNF), neurturin (NTN), persephin (P SP), GFR alpha-1, GFR alpha-2, GFR alpha-3 and RET mRNA in human fetal spin al cord was studied. Strong GDNF mRNA hybridization signal, presumably rest ricted to Clarke's nucleus, was detected in the thoracic spinal cord, mRNA encoding GFR alpha-1 was expressed in the entire spinal cord gray matter wi th particularly high expression in the ventral horn. GFR alpha-1 was also e xpressed more weakly in dorsal root ganglia. NTN and persephin mRNA were no t detected in either the fetal spinal cord or the dorsal root ganglia. mRNA coding for GFR alpha-2, however, was found in most cells of the spinal cor d gray matter. A strong expression of GFR alpha-3 mRNA was detected in dors al root ganglia cells and Schwann cells. The transducing receptor RET was e xpressed strongly in motorneurons and dorsal root ganglion neurons. We conc lude that basic features concerning the role of the GDNF family of ligands and their receptors revealed in rodents applies to humans. NeuroReport 10:1 433-1439 (C) 1999 Lippincott Williams & Wilkins.