Long term potentiation occurs when:
长期增强作用发生在：

Question

BlackTom AI · Accepted Answer

Long-term potentiation (LTP) is a Hebbian form of synaptic plasticity often summarized as "neurons that fire together, wire together," so the correct answer — neurons firing together increases synaptic strength — is supported by cellular and molecular mechanisms.

1. Relevant knowledge points and concepts
- Hebbian plasticity: synaptic strength increases when presynaptic and postsynaptic neurons are active together.
- Key receptors: AMPA (mediates fast EPSPs) and NMDA (coincidence detector blocked by Mg2+ at resting potential).
- Intracellular signaling: Ca2+ influx through NMDA receptors activates kinases (e.g., CaMKII), leading to AMPA receptor insertion and structural changes (spine growth), producing a long-lasting increase in synaptic efficacy.

2. Step-by-step reasoning
- Presynaptic neuron fires → releases glutamate into the synaptic cleft.
- If the postsynaptic neuron is sufficiently depolarized at the same time (i.e., they fire together), the Mg2+ block of NMDA receptors is relieved.
- Glutamate + relieved Mg2+ block → NMDA receptor opens, allowing Ca2+ influx.
- Elevated intracellular Ca2+ activates kinases (CaMKII, PKC) that phosphorylate proteins and promote trafficking/insertion of additional AMPA receptors into the postsynaptic membrane.
- More AMPA receptors = larger postsynaptic response to subsequent glutamate release → potentiation that can last minutes to hours or longer due to structural changes.

3. (No numerical calculations apply.)

4. Why the correct answer is correct
- The NMDA receptor requirement enforces coincidence detection: only simultaneous presynaptic glutamate release and postsynaptic depolarization produce the biochemical cascade that strengthens the synapse. Thus “neurons fire together” directly causes increased synaptic strength.

5. Why other possible answers would be incorrect
- Presynaptic firing alone without postsynaptic depolarization does not relieve NMDA Mg2+ block and typically won’t induce LTP.
- Low-frequency or asynchronous activity tends to produce long-term depression (LTD), the opposite effect.

6. Conclusion
The provided answer — neurons fire together increases synaptic strength — correctly states the core principle and mechanism of LTP.

Long term potentiation occurs when: 长期增强作用发生在：单项选择题

类似问题

The research team want to induce long-term potentiation (LTP) in synapses onto AgRP neurons, following Hebbian principles. Which of the following stimulation protocols would be most appropriate Note: 1 Hz = 1 cycle / second, or 1 stimulus per second.

Dendritic spines may change morpholgoically (changing size) depending on synaptic input.

Long term potentiation occurs when:

What role do AMPA receptors play at synapses that exhibit NMDA mediated long-term potentiation?

Some forms of synaptic potentiation require calcium ion entry into the post-synaptic neuron via NMDA receptors. Which of the following is NOT a direct action of this increased post-synaptic calcium?

Which of the following statements represent/s evidence that synaptic plasticity among engram cells is involved in memory processing?

What role do AMPA receptors play at synapses that exhibit NMDA mediated long-term potentiation? AMPA 受体在表现出 NMDA 介导的长时程增强作用的突触中发挥什么作用？

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单