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BIO254:Silent: Difference between revisions
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[[BIO254:LTP|Long-term potentiation]] (LTP) describes the process wherein the synaptic efficacy of two neurons is strengthened over time, in a way that depends on the simultaneity of firing (spike timing dependent plasticity). The best-studied form of this is hippocampal CA3-CA1 LTP, demonstrated by Timothy Bliss and Terje Lomo (1973). Brief high-frequency (tetanic) stimulation of a presynaptic cell can result in long-term enhancement of synaptic transmission. LTP additionally exhibits the following properties: | [[BIO254:LTP|Long-term potentiation]] (LTP) describes the process wherein the synaptic efficacy of two neurons is strengthened over time, in a way that depends on the simultaneity of firing (spike timing dependent plasticity). The best-studied form of this is hippocampal CA3-CA1 LTP, demonstrated by Timothy Bliss and Terje Lomo (1973). Brief high-frequency (tetanic) stimulation of a presynaptic cell can result in long-term enhancement of synaptic transmission. LTP additionally exhibits the following properties: | ||
Cooperativity: The probability of inducing LTP increases with the number of stimulated afferents, and the strength of their stimulation. This reflects a postsynaptic depolarization threshold that must be exceeded in order to induce LTP. | * '''Cooperativity''': The probability of inducing LTP increases with the number of stimulated afferents, and the strength of their stimulation. This reflects a postsynaptic depolarization threshold that must be exceeded in order to induce LTP. | ||
Input specificity: LTP is restricted to the synapses that triggered the process, and does not propagate to nearby synapses. | * '''Input specificity''': LTP is restricted to the synapses that triggered the process, and does not propagate to nearby synapses. | ||
Associativity: Weak stimulation on one pathway may be insufficient to induce LTP, though when coupled with strong stimulation on another, LTP can be induced on both pathways. | * '''Associativity''': Weak stimulation on one pathway may be insufficient to induce LTP, though when coupled with strong stimulation on another, LTP can be induced on both pathways. | ||
It was found that CA3-CA1 LTP requires both NMDAR and Ca<sup>2+</sup>, and involves depolarization of the postsynaptic cell, activation of NMDA receptors in that cell, the resulting influx of Ca<sup>2+</sup>, and the activation of secondary messengers by Ca<sup>2+</sup>. | It was found that CA3-CA1 LTP requires both NMDAR and Ca<sup>2+</sup>, and involves depolarization of the postsynaptic cell, activation of NMDA receptors in that cell, the resulting influx of Ca<sup>2+</sup>, and the activation of secondary messengers by Ca<sup>2+</sup>. | ||
