title: A quantitative study of the neuronal nitric oxide synthase expression in the superficial layers of the adult rat superior colliculus after perinatal enucleation.
abstract: The level of expression of the neuronal nitric oxide synthase (nNOS) in the retinorecipient layers of rat superior colliculus (SC) was investigated in adult rats after neonatal enucleation using two biochemical methods: (1) measurement of the in vitro specific-activity of NOS by the conversion of [3H]-arginine to [3H]-citrulline and (2) immunochemical analysis by western blotting and densitometry of immunoreactive bands using antibodies that recognise the three prominent isoforms of nNOS, alpha, beta and gamma. A total of 20 Lister rats were used in this study. We have shown that the deprivation of the retinocollicular projections at early postnatal ages induces no significant change in the specific-activity of nNOS. We also have shown that the deafferentation does not significantly influence either the total amount of nNOS in the SC superficial layers or the relative contribution ratio of nNOS isoforms. In conclusion, the expression and activity of nNOS in the SC retinorecipient layers was shown not to be dependent on the presence of retinal afferents during development.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil.
authors.forename: Ruben Ernesto
authors.initials: RE
authors.lastname: de Bittencourt-Navarrete
authors.forename: Arthur
authors.initials: A
authors.lastname: Giraldi-Guimarães
authors.forename: Rosalia
authors.initials: R
authors.lastname: Mendez-Otero
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001120:Arginine / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D002956:Citrulline / Q000378:metabolism; D003720:Densitometry / Q000379:methods; D015353:Eye Enucleation / Q000379:methods; D007839:Functional Laterality / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D013477:Superior Colliculi / Q000033:anatomy & histology / Q000201:enzymology* / Q000254:growth & development; D014316:Tritium / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D014316:Tritium; D002956:Citrulline; D001120:Arginine; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat