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BIO254:Silent: Difference between revisions
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→Molecular Mechanisms Underlying LTP
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==Molecular Mechanisms Underlying LTP== | ==Molecular Mechanisms Underlying LTP== | ||
Although LTP was discovered more than three decades ago, the molecular mechanisms contributing to this phenomenon are still not well understood. The properties of NMDA-type glutamate receptors were first elucidated in the mid-1980s, and at about the same time, neurobiologists found that antagonists (inhibitors) of NMDA receptors actually prevented LTP. The "and" characteristics of NMDA receptors contribute to both the specificity and associativity of LTP. For example, when only one group of synaptic inputs is strongly stimulated, LTP is confined to the active synapses since glutamate opens NMDA receptors only at the stimulated sites. However, in associativity, applying a weakly stimulating input current releases glutamate but it cannot depolarize the post-synaptic terminal enough to relieve the Mg++ block. When neighboring stimulations are applied to a weak input, these currents work "associatively" to both depolarize and unblock the NMDA receptors on the cell dendrite. | Although LTP was discovered more than three decades ago, the molecular mechanisms contributing to this phenomenon are still not well understood. The properties of NMDA-type glutamate receptors were first elucidated in the mid-1980s, and at about the same time, neurobiologists found that antagonists (inhibitors) of NMDA receptors actually prevented LTP. The "and" characteristics of NMDA receptors contribute to both the specificity and associativity of LTP. For example, when only one group of synaptic inputs is strongly stimulated, LTP is confined to the active synapses since glutamate opens NMDA receptors only at the stimulated sites. However, in associativity, applying a weakly stimulating input current releases glutamate but it cannot depolarize the post-synaptic terminal enough to relieve the Mg++ block. When neighboring stimulations are applied to a weak input, these currents work "associatively" to both depolarize and unblock the NMDA receptors on the cell dendrite. | ||
