title: Effect of Brn-3a deficiency on parvalbumin-immunoreactive primary sensory neurons in the dorsal root ganglion.
abstract: Immunohistochemistry for parvalbumin, a marker for primary proprioceptors, was performed on the dorsal root ganglion (DRG) of wildtype and knockout mice for Brn-3a at postnatal day 0 and embryonic day 18.5. The DRG contained many parvalbumin-immunoreactive (ir) neurons in wildtype (5.4%) and knockout mice (5.6%). Cell size analysis demonstrated that such neurons were mostly medium-sized to large in these mice. Therefore, it is unlikely that the survival of proprioceptors is dependent upon Brn-3a in the DRG. In the dorsal column and gray matter of the spinal cord of knockout mice, however, parvalbumin-ir nerve fibers were sparse compared to wildtype mice. The number of parvalbumin-ir varicosities around motoneurons decreased in the mutant. Thus, our data suggest that Brn-3a may play an important role in the central projection and terminal formation of DRG proprioceptors in the spinal cord.
authors.affiliation: Department of Oral Function and Anatomy, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan. hiroichi@md.okayama-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Z
authors.initials: Z
authors.lastname: Mo
authors.forename: M
authors.initials: M
authors.lastname: Xiang
authors.forename: T
authors.initials: T
authors.lastname: Sugimoto
mesh_terms: D000344:Afferent Pathways / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D048429:Cell Size / Q000235:genetics; D004268:DNA-Binding Proteins / Q000172:deficiency* / Q000235:genetics; D005727:Ganglia, Spinal / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D020439:Growth Cones / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D008465:Mechanoreceptors / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009413:Nerve Fibers, Myelinated / Q000378:metabolism / Q000648:ultrastructure; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D011434:Proprioception / Q000235:genetics; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D050818:Transcription Factor Brn-3; D050819:Transcription Factor Brn-3A; D014157:Transcription Factors / Q000172:deficiency* / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D010320:Parvalbumins; C494189:Pou4f1 protein, mouse; D050818:Transcription Factor Brn-3; D050819:Transcription Factor Brn-3A; D014157:Transcription Factors