title: Failure to disrupt development of cholinergic fiber patches in the superior colliculus in nitric oxide synthase deficient mice.
abstract: Nitric oxide (NO) has been shown to mediate refinement of glutamatergic axonal pathways during development. In this study, we investigated whether the development of a cholinergic pathway in the intermediate gray layer (IGL) of the mouse superior colliculus (SC) is also mediated by NO. The pathway was labeled using an antibody directed against choline acetyltransferase (ChAT) and its distribution examined in normal C57/BL6 mice and in knockout mice in which the genes for the neuronal isoform of nitric oxide synthase (NOS) or both the endothelial and neuronal isoforms of NOS had been disrupted. We also examined the development of expression of NOS using nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) staining. NADPHd labeled cells were found within the IGL by P8 and formed loose clusters of cells by P12-P15. ChAT and NADPHd labeled fibers were first observed at P12 and gradually established their characteristic two-tiered patchy pattern between P14 and P21. Comparison of the ChAT labeled fiber distribution in normal, single nNOS and double e,nNOS knockout mice revealed no differences between these three groups. We therefore conclude that nitric oxide does not mediate refinement of this cholinergic pathway.
authors.affiliation: Department of Cell Biology and Anatomy and the Neuroscience Center, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112-1393, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Scheiner
authors.forename: R J
authors.initials: RJ
authors.lastname: Cork
authors.forename: R R
authors.initials: RR
authors.lastname: Mize
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D002799:Cholinergic Fibers / Q000201:enzymology / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout / Q000235:genetics; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000172:deficiency* / Q000235:genetics; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D013477:Superior Colliculi / Q000201:enzymology / Q000254:growth & development*
chemical_list: D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496321:Nos1 protein, mouse; C496315:Nos3 protein, mouse; D009252:NADPH Dehydrogenase; D002795:Choline O-Acetyltransferase