NMDA-induced whole-cell currents and single channel conductances in tectal neurons during two stages of early development of chicken

Föhr, K.J.; Schirm, Thomas; Finger, W.

doi:10.1016/0304-3940(94)11121-x

Cited by 7 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first aim of this study was to examine the role of NMDA receptors in elimination of the ipsilateral retinotectal projection during chick development. Retinal ganglion cells are glutamatergic (Kalloniatis et al, 1994;Dye and Karten, 1996) and make synaptic connections with cells that express NMDA receptors (Esguerra et al, 1992;Cline et al, 1994;Fohr et al, 1995;Guido et al, 1997). To determine whether retinotectal communication mediated by NMDA receptors is important in elimination of the ipsilateral projection, we treated embryos with an NMDA receptor antagonist, MK-801, during the period of refinement.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies showed that activation of NMDA receptors resulted in the synthesis of NO in cultured cerebellar granule cells (Garthwaite et al, 1988;Bredt and Snyder, 1989). Because both NMDA receptors and NOS are expressed in the developing tectum (Esguerra et al, 1992;Cline et al, 1994;Williams et al, 1994;Fohr et al, 1995;Guido et al, 1997), it is likely that activation of NMDA receptors in the tectum leads to synthesis of NO. The present study implies a link between NMDA receptor activation and NO synthesis by showing a reduction in NOS activity in tectal cells after treatment of embryos with MK-801 in vivo.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

NMDA Receptor-Mediated Refinement of a Transient Retinotectal Projection during Development Requires Nitric Oxide

Ernst¹,

Wu²,

El‐Fakahany

et al. 1999

J. Neurosci.

View full text Add to dashboard Cite

A transient ipsilateral retinotectal projection is normally eliminated during embryonic development of the chick visual system. Administration of the NMDA receptor antagonist 5-methyl-10, 11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801) during the developmental period in which this projection normally disappears prevented its complete elimination. Previous studies showed that tectal cells express nitric oxide synthase during development, and blocking synthesis of nitric oxide also prevented elimination of the ipsilateral retinotectal projection. The effect of NMDA receptor blockade on nitric oxide synthase activity in tectal cells was assessed biochemically in chick embryos. Increasing concentrations of MK-801 resulted in a dose-dependent decrease in nitric oxide synthase activity. This result suggests that NMDA receptor activation can regulate nitric oxide synthase activity in the tectum. The degree of rescue of the ipsilateral retinotectal projection was compared in embryos treated either with MK-801 or with an inhibitor of nitric oxide synthesis, Nomega-nitro-L-arginine (L-NoArg). At comparable levels of inhibition of nitric oxide synthesis, no significant difference was observed in the degree of rescue mediated by NMDA receptor blockade or nitric oxide synthesis blockade. These results suggest that NMDA receptor-mediated elimination of the ipsilateral retinotectal projection is completely mediated via nitric oxide.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

NMDA Receptor-Mediated Refinement of a Transient Retinotectal Projection during Development Requires Nitric Oxide

Ernst¹,

Wu²,

El‐Fakahany

et al. 1999

J. Neurosci.

View full text Add to dashboard Cite

show abstract

“…There are many possibilities. Functional NMDA receptors are present in the early chicken embryo (38) and there is evidence from Western blots that the NR1 subunit protein is already present by stage 10, during the first 34 h of development (M. Thomas, personal communication). The NMDA receptor is a heterooligomer composed of NR1( a‐h ), NR2 (A‐D) , and NR3 subunits (39–42); thus, there is the potential for multiple combinations in the receptor complex.…”

Section: Discussionmentioning

confidence: 99%

N‐methyl‐D‐aspartate receptor agonists modulate homocysteine‐induced developmental abnormalities

1999

View full text Add to dashboard Cite

We showed previously that the induction of neural crest (NC) and neural tube (NT) defects is a general property of N-methyl-D-aspartate receptor (NMDAR) antagonists. Since homocysteine induces NC and NT defects and can also act as an NMDAR antagonist, we hypothesized that the mechanism of homocysteine-induced developmental defects is mediated by competitive inhibition of the NMDAR by homocysteine. If this hypothesis is correct, homocysteine-induced defects will be reduced by NMDAR agonists. To test the hypothesis, we treated chicken embryos during the process of neural tube closure with sufficient homocysteine thiolactone to induce NC and NT defects in approximately 40% of survivors or with homocysteine thiolactone in combination with each of a selected set of NMDAR agonists in 0. 05-5000 nmol doses. Glutamate site agonists selected were L-glutamate and N-methyl-D-aspartate. Glycine site agonists were glycine, D-cycloserine, and aminocyclopropane-carboxylic acid. Glycine was the most effective overall, reducing defects significantly at two different doses (each P>0.001). These results support the hypothesis that homocysteine may affect NC and NT development by its ability to inhibit the NMDAR. One potentially important consequence of this putative mechanism is that homocysteine may interact synergistically with other NMDAR antagonists to enhance its effect on development.

show abstract

Potential Role of Endogenous Brain-Derived Neurotrophic Factor in Long-Term Neuronal Reorganization of the Superior Colliculus after Bilateral Visual Deprivation

Vizuete

Venero

Vargas

et al. 2001

Neurobiology of Disease

View full text Add to dashboard Cite

NMDA-induced whole-cell currents and single channel conductances in tectal neurons during two stages of early development of chicken

Cited by 7 publications

References 9 publications

NMDA Receptor-Mediated Refinement of a Transient Retinotectal Projection during Development Requires Nitric Oxide

NMDA Receptor-Mediated Refinement of a Transient Retinotectal Projection during Development Requires Nitric Oxide

N‐methyl‐D‐aspartate receptor agonists modulate homocysteine‐induced developmental abnormalities

Potential Role of Endogenous Brain-Derived Neurotrophic Factor in Long-Term Neuronal Reorganization of the Superior Colliculus after Bilateral Visual Deprivation

Contact Info

Product

Resources

About