Anterograde axonal transport of BDNF and NT-3 by retinal ganglion cells: roles of neurotrophin receptors.
Retinal ganglion cells (RGCs) transport exogenous neurotrophins anterogradely to the midbrain tectum/superior colliculus with significant downstream effects. We determined contributions of neurotrophin receptors for anterograde transport of intraocularly injected radiolabeled neurotrophins. In adult rodents, anterograde transport of brain-derived neurotrophic factor (BDNF) was receptor-mediated, and transport of exogenous BDNF and neurotrophin-3 (NT-3) was more efficient, per RGC, in rodents than chicks. RT-PCR and Western blot analysis of purified murine RGCs showed that adult RGCs express the p75 receptor. Anterograde transport of BDNF or NT-3 was not diminished in p75 knock-out mice (with unaltered final numbers of RGCs), but BDNF transport was substantially reduced by co-injected trkB antibodies. In chick embryos, however, p75 antisense or co-injected p75 antibodies significantly attenuated anterograde transport of NT-3 by RGCs. Thus, neither BDNF nor NT-3 utilizes p75 for anterograde transport in adult rodent RGCs, while anterograde NT-3 transport requires the p75 receptor in embryonic chicken RGCs.
Butowt
Rafal
R
Department of Physiology and Cell Biology, Mailstop 352, University of Nevada School of Medicine, Reno, NV 89557, USA.
von Bartheld
Christopher S
CS
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001370:Axonal Transport / Q000502:physiology*; D019208:Brain-Derived Neurotrophic Factor / Q000493:pharmacokinetics*; D002642:Chick Embryo; D002645:Chickens; D007457:Iodine Radioisotopes; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D020933:Neurotrophin 3 / Q000493:pharmacokinetics*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D020800:Receptor, Nerve Growth Factor; D020813:Receptor, trkB / Q000276:immunology; D017475:Receptors, Nerve Growth Factor / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000378:metabolism*; D013477:Superior Colliculi / Q000166:cytology / Q000378:metabolism
D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; D007457:Iodine Radioisotopes; D020933:Neurotrophin 3; D016376:Oligonucleotides, Antisense; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D020813:Receptor, trkB