title: Characterization of sensory neurons in the dorsal root ganglia of Bax-deficient mice.
abstract: During development, the rescue of spinal motoneurons as well as sensory neurons in the dorsal root ganglion (DRG) from programmed cell death (PCD) depends on the integrity of peripheral target innervation. Following deletion of the pro-apoptotic gene Bax, both motoneurons and DRG neurons are rescued from PCD. In the present paper, we asked whether different cell types in the DRG exhibit distinct responses to Bax deletion. In 1-month-old Bax-deficient (Bax-/-) mice, distinct subsets of DRG neurons that were immunopositive for TrkA, CGRP, TRPV1 or TrkC, were all increased in number and exhibited cell atrophy compared to wild type DRG neurons. In addition there was hyperinnervation of the epidermis by CGRP immunopositive processes and a correlated functional hypersensitivity of mechanical nociception in Bax-/- mice. By contrast, the functional properties of populations of rescued thermoreceptor and mechanoreceptor DRG neurons were unchanged. These data indicate that although Bax deletion rescues all of the DRG cell types examined here from PCD, the functional consequences of having excess cells differ between sensory phenotypes.
authors.affiliation: Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Youhei
authors.initials: Y
authors.lastname: Aoyama
authors.forename: Kouji
authors.initials: K
authors.lastname: Senzaki
authors.forename: Michelle
authors.initials: M
authors.lastname: Vincler
authors.forename: Shannon
authors.initials: S
authors.lastname: Wittenauer
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ozaki
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Oppenheim
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiga
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000235:genetics*; D051017:Apoptosis Regulatory Proteins / Q000172:deficiency* / Q000235:genetics; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011984:Sensory Receptor Cells / Q000145:classification / Q000166:cytology / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000172:deficiency* / Q000235:genetics
chemical_list: D051017:Apoptosis Regulatory Proteins; D051028:bcl-2-Associated X Protein