title: Evidence for increased GDNF signaling in aged sensory and motor neurons.
abstract: Several lines of evidence suggest that attenuated neurotrophin signaling may account for some of the aging-related phenotypic changes observed in motor and sensory neurons. Glial-derived neurotrophic factor (GDNF) signals through the GFRalpha-1-RET receptor complex and has trophic effects on both primary sensory neurons and, in particular, motoneurons. In this study we provide evidence using RT-PCR that GDNF, but not neurturin, is strongly up-regulated in target muscles (800%) and to a lesser extent also in peripheral supportive tissues. Results here, and in an earlier study, show that the up-regulation of GDNF in target and supportive tissues parallels an increased neuronal expression of the cognate receptors. Increased GDNF signaling may explain some of the phenotypic characteristics of aging sensory and motoneurons.
authors.affiliation: Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Y
authors.initials: Y
authors.lastname: Ming
authors.forename: E
authors.initials: E
authors.lastname: Bergman
authors.forename: E
authors.initials: E
authors.lastname: Edström
authors.forename: B
authors.initials: B
authors.lastname: Ulfhake
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009046:Motor Neurons / Q000502:physiology*; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*
chemical_list: C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins