title: Osteopontin-immunoreactive primary sensory neurons in the rat spinal and trigeminal nervous systems.
abstract: 1200 micrometer(2) and 9% of those in the range 600-1200 micrometer(2) showed the immunoreactivity (ir). DRG neurons <600 micrometer(2)800 micrometer(2) showed the ir and 21% of those in the range 400-800 micrometer(2) were immunoreactive for this protein. TG neurons <400 micrometer(2) were mostly devoid of OPN-ir (2%). Virtually all (99%) Mes5 primary sensory neurons exhibited the ir. Muscle spindles in the soleus and masseter muscles contained OPN-ir spiral axon terminals. In the hard palate and incisor periodontal ligament, unencapsulated corpuscular endings exhibited the ir. The co-expression of OPN with parvalbumin and calcitonin gene-related peptide (CGRP) was also examined in the DRG and TG. In the DRG, virtually all (97%) OPN-ir neurons exhibited parvalbumin-ir. Conversely, 66% of parvalbumin-ir DRG neurons co-expressed OPN-ir. In the TG, 81% of OPN-ir neurons exhibited parvalbumin-ir and 69% of parvalbumin-ir ones showed OPN-ir. Virtually all OPN-ir DRG and TG neurons were devoid of CGRP-ir. The present study indicates that OPN-ir primary sensory neurons in the DRG and Mes5 are spinal and trigeminal proprioceptors. OPN-ir TG neurons appear to include low-threshold mechanoreceptors.
authors.affiliation: Second Department of Oral Anatomy, Okayama University Dental School, 2-5-1 Shikata-Cho, Okayama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ichikawa
authors.forename: T
authors.initials: T
authors.lastname: Itota
authors.forename: Y
authors.initials: Y
authors.lastname: Nishitani
authors.forename: Y
authors.initials: Y
authors.lastname: Torii
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D048429:Cell Size / Q000502:physiology; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009470:Muscle Spindles / Q000166:cytology / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000294:innervation / Q000378:metabolism; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism*; D053495:Osteopontin; D010320:Parvalbumins / Q000378:metabolism; D010513:Periodontal Ligament / Q000166:cytology / Q000294:innervation / Q000378:metabolism; D010525:Peripheral Nerves / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012795:Sialoglycoproteins / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000378:metabolism*; D014278:Trigeminal Nuclei / Q000166:cytology / Q000378:metabolism*
chemical_list: D010320:Parvalbumins; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D015740:Calcitonin Gene-Related Peptide