title: S100 protein-immunoreactive primary sensory neurons in the trigeminal and dorsal root ganglia of the rat.
abstract: The cell body size (cross-sectional area) of S100-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG). About a half of neurons exhibited S100-immunoreactivity (-ir) in the DRG (44.0%) and TG (59.0%). DRG neurons with cell bodies > 1200 microm2 mostly exhibited S100-ir (96.5%), whereas S100-ir DRG neurons < 600 microm2 were rare (8.0%). 36.6% of DRG neurons in the cell size range 600-1200 microm2 showed the ir. TG neurons > 800 microm2 mostly exhibited S100-ir (93.1%), whereas those < 400 microm2 were devoid of it (positive cells 10.5%). 58.3% of TG cells in the range 400-800 microm2 contained S100-ir. Double-immunofluorescence method revealed the co-expression of S100 and other calcium-binding proteins. Parvalbumin-ir neurons mostly exhibited S100-ir in the DRG (97.4%) and TG (97.0%). The co-expression of S100 and calbindin D-28k was very rare in the DRG, because the DRG contained few calbindin D-28k-ir neurons. Unlike in the DRG, numerous neurons co-expressed S100- and calbindin D-28k-ir in the TG. Most calbindin D-28k-ir TG neurons were also immunoreactive for S100 (90.7%). Sub-populations of calretinin (CR)-ir neurons co-expressed S100-ir in both the DRG (68%) and TG (50.0%). Virtually all CR-ir neurons > 1400 microm2 co-expressed S100-ir in the DRG (100%) and TG (95.9%). CR-ir neurons < 800 microm2 were rarely exhibited S100-ir (DRG 18.0%, TG 21.9%). 71.3 and 60.5% of CR-ir neurons in the range 800-1400 microm2 co-expressed S100-ir in the DRG and TG, respectively. The present study indicates that S100 is closely correlated to the primary neuronal cell size in the DRG and TG.
authors.affiliation: Second Department of Oral Anatomy, Okayama University Dental School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ichikawa
authors.forename: D M
authors.initials: DM
authors.lastname: Jacobowitz
authors.forename: T
authors.initials: T
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D064032:Calbindin 2; D064026:Calbindins; D005455:Fluorescent Antibody Technique; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D009418:S100 Proteins / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000378:metabolism*
chemical_list: C576512:Calb2 protein, rat; D064032:Calbindin 2; D064026:Calbindins; D009419:Nerve Tissue Proteins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G; D009418:S100 Proteins