title: NADPH-diaphorase activity in the nociceptive pathways of land snail Megalobulimus abbreviatus: the involvement of pedal ganglia.
abstract: NADPH-diaphorase (NADPH-d) is a histochemical marker for nitric oxide synthase (NOS), widely used to identify nitric oxide (NO) producing cells in the nervous system of both vertebrates and invertebrates. Using NADPH-d histochemistry and semi-quantitative optical densitometry, we characterized the NO-producing neurons in the pedal ganglia of young and adult Megalobulimus abbreviatus, subjected to aversive thermal stimulus. The animals were killed at different times (3, 6, 12 and 24 h) following stimulus. The enzymatic activity was detected in different cellular subsets and neuronal processes. In all the studied pedal ganglia subregions, the optical density of positive neurons (P < 0.05) and neuropilar area 1 (P < 0.01) was significantly different in treated animals when compared to controls. The increase in nitrergic activity induced by nociceptive stimulus suggests the involvement of NO in the nociceptive circuit of M. abbreviatus, which is well maintained throughout evolution, and could be helpful in drawing cellular homologies with other gastropods.
authors.affiliation: Programa de Pós-Graduação em Neurociências Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Paula
authors.initials: P
authors.lastname: Rigon
authors.forename: Juliana
authors.initials: J
authors.lastname: de Castilhos
authors.forename: Lisiani
authors.initials: L
authors.lastname: Saur
authors.forename: Mariana F
authors.initials: MF
authors.lastname: Rodrigues
authors.forename: Matilde
authors.initials: M
authors.lastname: Achaval
authors.forename: Léder L
authors.initials: LL
authors.lastname: Xavier
mesh_terms: D000818:Animals; D017952:Ganglia, Invertebrate / Q000378:metabolism*; D007150:Immunohistochemistry; D009252:NADPH Dehydrogenase / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D012908:Snails / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide; D009252:NADPH Dehydrogenase