GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:15590926

From GONUTS
Jump to: navigation, search
Citation

Townsend, M, Liu, Y and Constantine-Paton, M (2004) Retina-driven dephosphorylation of the NR2A subunit correlates with faster NMDA receptor kinetics at developing retinocollicular synapses. J. Neurosci. 24:11098-107

Abstract

We describe a homeostatic mechanism that limits NMDA receptor currents in response to early light activation of a developing visual pathway. During the second postnatal week of rodent retinocollicular development, the Ca2+-activated phosphatase calcineurin (CaN) mediates a rapid, activity-induced shortening in the decay time of NMDA receptor (NMDAR) currents. We show that protein kinase A acts in opposition to CaN to maintain NMDAR currents with long decay times. The CaN-mediated change is coincident with the initial expression of the NMDAR subunit NR2A. Using NR2A knock-out mice and dialyzing neurons with a constitutively active CaN, we demonstrate that NR2A subunits are necessary for the effect of CaN on NMDAR current kinetics. In wild-type mice, Ser900 of NR2A, previously implicated in CaN-mediated glycine-independent desensitization, becomes chronically dephosphorylated by postnatal day 11 as NMDAR current decay times become faster. Pharmacologically disrupting early photoreceptor-driven activity in the retina eliminates the dephosphorylation of NR2A and prevents the shortening in NMDAR current decay time. These data suggest that the developmental onset of retinal activity increases CaN-mediated dephosphorylation of NR2A subunits newly incorporated into synaptic NMDARs of the superior colliculus, thereby providing a mechanism for the early and rapid reduction of NMDAR current decay time in visual neurons.

Links

PubMed Online version:10.1523/JNEUROSCI.1207-04.2004

Keywords

Animals; Calcineurin/physiology; Cyclic AMP-Dependent Protein Kinases/physiology; Electrophysiology; Kinetics; Mice; Mice, Knockout; Phosphorylation; Receptors, N-Methyl-D-Aspartate/metabolism; Receptors, N-Methyl-D-Aspartate/physiology; Retina/growth & development; Retina/physiology; Retinal Ganglion Cells/physiology; Serine/metabolism; Superior Colliculi/growth & development; Superior Colliculi/physiology; Synapses/physiology; Visual Pathways/growth & development; Visual Pathways/physiology

Significance

Annotations

Gene product Qualifier GO ID GO term name Evidence Code with/from Aspect Notes Status


See also

References

See Help:References for how to manage references in GONUTS.