title: Glial cell line-derived neurotrophic factor (GDNF) is required for differentiation of pontine noradrenergic neurons and patterning of central respiratory output.
abstract: Genetic mutations affecting signaling by glial cell line-derived neurotrophic factor (GDNF) perturb development of breathing in mice and are associated with congenital central hypoventilation syndrome in humans. However, the role of GDNF in development of brainstem neurons that control breathing is largely unknown. The present study demonstrates that genetic loss of GDNF decreases the number of tyrosine hydroxylase (TH) neurons in the pontine A5 noradrenergic cell group, a major source of inhibitory input to the medullary respiratory pattern generator. This phenotype is associated with a significant increase in the frequency of central respiratory output recorded from the fetal medulla-spinal cord in vitro. In dissociate cultures of the A5 region from rat embryos, GDNF increases TH cell number and neurite growth without affecting total neuronal survival or proliferation of TH neurons. These effects of GDNF are inhibited by function blocking antibodies against endogenous brain-derived neurotrophic factor (BDNF), indicating that GDNF requires BDNF as a cofactor to stimulate differentiation of A5 neurons. Our findings demonstrate that GDNF is required for development of pontine noradrenergic neurons in vivo and indicate that defects in the A5 cell group may contribute to the effects of genetic disruption of GDNF signaling on respiratory control.
authors.affiliation: Department of Pediatrics, University Hospitals of Cleveland, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
authors.forename: L
authors.initials: L
authors.lastname: Huang
authors.forename: H
authors.initials: H
authors.lastname: Guo
authors.forename: D T
authors.initials: DT
authors.lastname: Hellard
authors.forename: D M
authors.initials: DM
authors.lastname: Katz
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000276:immunology / Q000494:pharmacology; D002452:Cell Count / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D048429:Cell Size; D002478:Cells, Cultured; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004347:Drug Interactions; D004594:Electrophysiology / Q000379:methods; D004622:Embryo, Mammalian; D005260:Female; D005838:Genotype; D051100:Glial Cell Line-Derived Neurotrophic Factor; D007150:Immunohistochemistry / Q000379:methods; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009414:Nerve Growth Factors / Q000502:physiology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D011149:Pons / Q000166:cytology* / Q000196:embryology; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012125:Respiratory Center / Q000502:physiology*; D014404:Tubulin / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; C495040:Gdnf protein, mouse; C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D014404:Tubulin; D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase; D009638:Norepinephrine