1. Blockade of GluN2B-Containing NMDA Receptors Prevents Potentiation and Depression of Responses during Ocular Dominance Plasticity.
- Author
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Bridi MCD, Hong S, Severin D, Moreno C, Contreras A, and Kirkwood A
- Subjects
- Animals, Mice, Male, Female, Evoked Potentials, Visual physiology, Visual Cortex physiology, Visual Cortex drug effects, Excitatory Amino Acid Antagonists pharmacology, Sensory Deprivation physiology, Long-Term Potentiation physiology, Long-Term Potentiation drug effects, Long-Term Synaptic Depression physiology, Long-Term Synaptic Depression drug effects, Photic Stimulation methods, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors, Receptors, N-Methyl-D-Aspartate metabolism, Dominance, Ocular physiology, Neuronal Plasticity physiology, Neuronal Plasticity drug effects, Mice, Inbred C57BL, Excitatory Postsynaptic Potentials physiology, Excitatory Postsynaptic Potentials drug effects
- Abstract
Monocular deprivation (MD) causes an initial decrease in synaptic responses to the deprived eye in juvenile mouse primary visual cortex (V1) through Hebbian long-term depression (LTD). This is followed by a homeostatic increase, which has been attributed either to synaptic scaling or to a slide threshold for Hebbian long-term potentiation (LTP) rather than scaling. We therefore asked in mice of all sexes whether the homeostatic increase during MD requires GluN2B-containing NMDA receptor activity, which is required to slide the plasticity threshold but not for synaptic scaling. Selective GluN2B blockade from 2-6 d after monocular lid suture prevented the homeostatic increase in miniature excitatory postsynaptic current (mEPSC) amplitude in monocular V1 of acute slices and prevented the increase in visually evoked responses in binocular V1 in vivo . The decrease in mEPSC amplitude and visually evoked responses during the first 2 d of MD also required GluN2B activity. Together, these results support the idea that GluN2B-containing NMDA receptors first play a role in LTD immediately following eye closure and then promote homeostasis during prolonged MD by sliding the plasticity threshold in favor of LTP., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 the authors.)
- Published
- 2024
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