title: Complete sciatic nerve transection induces increase of neuropeptide Y-like immunoreactivity in primary sensory neurons and spinal cord of frogs.
abstract: Neuropeptide Y (NPY) was immunohistochemically investigated in the frog spinal cord and dorsal root ganglia after axotomy. In normal ganglia, moderate NPY-like immunoreactivity (NPY-IR) prevailed in large and medium cells. In the spinal cord, the NPY-IR was densest in the dorsal part of the lateral funiculus. Other fibers and neurons NPY-IR were observed in the dorsal and ventral terminal fields and mediolateral band. NPY-IR fibers were also found in the ventral horn and in the ventral and lateral funiculi. The sciatic nerve transection increased the NPY-IR in large and medium neurons of the ipsilateral and contralateral dorsal root ganglia at 3 and 7 days, but no clear change was found at 15 days. In the spinal cord, there was a bilateral increase in the NPY-IR of the dorsal part of the lateral funiculus. In the ipsilateral side, the NPY-IR was increased at 3 and 7 days but was decreased at 15 days. In the contralateral side, a significant reduction at 15 days occurred. These findings seem to favor the role of NPY in the modulation of pain-related information in frogs, suggesting that this role of NPY may have appeared early in vertebrate evolution.
authors.affiliation: Laboratório de Neurobiologia Comparada, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite, 500, 90050-170, Porto Alegre, RS, Brazil. reguedes@yahoo.com.br
authors.forename: Renata P
authors.initials: RP
authors.lastname: Guedes
authors.forename: Melina I
authors.initials: MI
authors.lastname: Marchi
authors.forename: Matilde
authors.initials: M
authors.lastname: Achaval
authors.forename: Wania A
authors.initials: WA
authors.lastname: Partata
mesh_terms: D000818:Animals; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism*; D009478:Neuropeptide Y / Q000032:analysis / Q000276:immunology* / Q000378:metabolism*; D011892:Rana catesbeiana; D012584:Sciatic Nerve / Q000293:injuries* / Q000601:surgery; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*; D013119:Spinal Cord Injuries
chemical_list: D009478:Neuropeptide Y