What is the role of NMDA receptors in synaptic plasticity?
Synaptic plasticity of NMDARs is particularly important because these receptors play a pivotal role in synaptic plasticity, such that changes in the strength of synaptic NMDARs are expected to critically influence the threshold for induction of AMPAR-mediated synaptic plasticity, as well as experience-dependent …
What role do NMDA and AMPA receptors play in long-term potentiation?
N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) and long-term depression (LTD) of signal transmission form neural circuits and thus are thought to underlie learning and memory. These mechanisms are mediated by AMPA receptor (AMPAR) trafficking in postsynaptic neurons.
How does synaptic plasticity relate to memory?
The synaptic plasticity and memory hypothesis asserts that activity-dependent synaptic plasticity is induced at appropriate synapses during memory formation and is both necessary and sufficient for the encoding and trace storage of the type of memory mediated by the brain area in which it is observed. Criteria for …
What are AMPA and NMDA receptors?
AMPA receptors are a type of glutamate receptors whose activation results in the influx of sodium and potassium ions. On the other hand, NMDA receptors are another type of glutamate receptor whose activation results in the influx of calcium ions in addition to the sodium and potassium ions.
Is AMPA excitatory or inhibitory?
AMPA receptors mediate the vast majority of fast excitatory transmission in the CNS. The control of the number of postsynaptic AMPA receptors is a fundamental mechanism of use-dependent plasticity of excitatory synapses, including long-term potentiation (LTP) and long-term depression (LTD) (Huganir and Nicoll, 2013).
How do AMPA and NMDA work together?
The AMPA receptor is paired with an ion channel so that when glutamate binds to this receptor, this channel lets sodium ions enter the post-synaptic neuron. The NMDA receptor is also paired with an ion channel, but this channel admits calcium ions into the post-synaptic cell.
What is the role of NMDA and AMPA receptors?
NMDA receptors are commonly thought to play a role in the development of cortical circuitry, primarily as mediators of activity-dependent plasticity (Kirkwood and Bear, 1994;Katz and Shatz, 1996). AMPA receptors are commonly thought to play a role in normal, ongoing transmission between neurons.
Why is synaptic plasticity studied in the hippocampus?
Long-term synaptic plasticity was first reported in 1973. Studying a pathway in the rabbit hippocampus, researchers discovered that rapidly and repeatedly activating the synapses made them stronger; the volume control was turned up and stayed that way. Long-term synaptic plasticity forms the model for memory storage.
Why is synaptic potentiation important for learning and memory?
In neuroscience, long-term potentiation (LTP) is a persistent strengthening of synapses based on recent patterns of activity. As memories are thought to be encoded by modification of synaptic strength, LTP is widely considered one of the major cellular mechanisms that underlies learning and memory.
How do AMPA and NMDA receptors work?
Activation of AMPA receptors induces sodium influx through the channels, which in turn overcomes the voltage-dependent Mg++ blockade of NMDA receptors. The calcium influx resulting from this triggers a series of signal transduction cascades involving kinases, phosphatases, and scaffolding proteins.
How are NMDA and AMPA receptors different?
The main difference between AMPA and NMDA is that only the sodium and potassium influx occur in AMPA receptors whereas, in NMDA receptors, calcium influx occurs in addition to sodium and potassium influx. They are nonselective, ligand-gated ion channels, which mainly allow the passage of sodium and potassium ions.
Do NMDA receptors have long-term plasticity?
Beyond their well-established role as triggers for LTP and LTD of fast synaptic transmission mediated by AMPA receptors, an expanding body of evidence indicates that NMDA receptors (NMDARs) themselves are also dynamically regulated and subject to activity-dependent long-term plasticity.
What is NMDA receptor hypofunction in the brain?
An increasing level of N-methyl-D-aspartate (NMDA) receptor hypofunction within the brain is associated with memory and learning impairments, with psychosis, and ultimately with excitotoxic brain injury. As the brain ages, the NMDA receptor system becomes progressively hypofunctional, contributing to decreases in memory and learning performance.
Do NMDA receptor antagonists affect memory and learning performance?
However, many studies have been devoted to characterizing the effect of NMDA receptor antagonist drugs on memory and learning. The cognitive effects of NMDA receptor antagonist drugs in animals provide strong support, for the proposal that decreases in NMDA receptor function can decrease memory and learning performance.
What is synaptic plasticity of NMDAR-mediated transmission?
Given the unique biophysical properties of NMDARs, synaptic plasticity of NMDAR-mediated transmission emerges as a particularly powerful mechanism for the fine tuning of information encoding and storage throughout the brain. Copyright © 2012 Elsevier Ltd. All rights reserved.