title: Effect of BDNF depletion on the formation of Ruffini endings in vibrissa follicles and the survival of their mechanoreceptive neurons in trigeminal ganglion.
abstract: We examined the influence of BDNF depletion in peripheral tissues on the formation of Ruffini endings and their neuronal survival by injections of neutralizable anti-BDNF antibody into mouse mystacial pads for periods of 5 days at different developmental stages of the Ruffini endings (the pre-formation stage from the 2nd to 6th day after birth, the formation stage from the 4th to 8th, or the post-formation stage from the 10th to 14th). The treatment at the pre-formation and formation stages caused a significant decrease in the number of Ruffini endings in vibrissa follicles. This decrease in Ruffini endings was accompanied with a significant increase in neuron apoptosis in the trigeminal ganglion (TG) in both stages. However, at the post-formation stage, the anti-BDNF injection showed no effect on the formation of the mechanoreceptors nor their neuronal survival. In the post-formation stage, the axoplasmic spins of Ruffini endings were circumferentially embraced with the cytoplasmic processes of terminal Schwann cells. The present study indicates that target-derived BDNF is essential for survival of mechanoreceptive nerves in the pre-formation and formation stages, but not in the post-formation stages of their development. It seems that Schwann cells participate in this switch-over of neuronal dependency on brain-derived neurotrophic factor.
authors.affiliation: Laboratory of Toxicology, Course of Veterinary Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, 1-1 Gakuen-cho, Cyuoku, Sakai 599-8531, Japan.
authors.forename: Shigenaga
authors.initials: S
authors.lastname: Shimizu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kiyomiya
authors.forename: Saburo
authors.initials: S
authors.lastname: Matsuo
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000172:deficiency* / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D008465:Mechanoreceptors / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009418:S100 Proteins / Q000378:metabolism; D012668:Trigeminal Ganglion / Q000166:cytology* / Q000254:growth & development; D043222:Ubiquitin Thiolesterase / Q000378:metabolism; D014738:Vibrissae / Q000166:cytology* / Q000294:innervation
chemical_list: D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; D009418:S100 Proteins; D043222:Ubiquitin Thiolesterase; C496976:Uchl1 protein, mouse