Nitric oxide in the retinotectal system: A signal but not a retrograde messenger during map refinement and segregation

René C. Rentería, Martha Constantine-Paton

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

The role of nitric oxide (NO) as a mediator of synaptic plasticity is controversial in both the adult and developing brain. NO generation appears to be necessary for some types of NMDA receptor-dependent synaptic plasticity during development but not for others. Our previous work using several NO donors revealed that Xenopus laevis retinal ganglion cell axons stop growing in response to NO exposure. We demonstrate here that the same response occurs in tectal neuron processes bathed in the NO donor S-nitrosocysteine (SNOC) and in RGC growth cones to which SNOC is very locally applied. We show that NO synthase (NOS) activity is present in the Rana pipiens optic tectum throughout development in a dispersed subpopulation of tectal neurons, although effects of NO on synaptic function in a Rana pipiens tectal slice were varied. We chronically inhibited NOS in doubly innervated Rana tadpole optic tecta using L-N(G)-nitroarginine methyl ester in Elvax. Despite significant NOS inhibition as measured biochemically, eye-specific stripes remained normally segregated. This suggests that NOS activity is not downstream of NMDA receptor activation during retinotectal synaptic competition because NMDA receptor activation is necessary for segregation of retinal afferents into ocular dominance stripes in the doubly innervated tadpole optic tectum. We conclude that NO has some signaling function in the retinotectal pathway, but this function is not critical to the mechanism that refines the projection and causes eye-specific stripes.

Original languageEnglish (US)
Pages (from-to)7066-7076
Number of pages11
JournalJournal of Neuroscience
Volume19
Issue number16
DOIs
StatePublished - Aug 15 1999

Keywords

  • Development
  • Doubly innervated rectum
  • Nitric oxide
  • Nitric oxide synthase
  • Optic rectum
  • Retinotectal projection
  • Synaptic plasticity
  • Three-eyed frog

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Nitric oxide in the retinotectal system: A signal but not a retrograde messenger during map refinement and segregation'. Together they form a unique fingerprint.

Cite this