Which statement best describes spike-timing–dependent plasticity (STDP) and its primary cellular mechanism?

Question

BlackTom AI · Accepted Answer

The question asks about spike-timing–dependent plasticity (STDP) and its primary cellular mechanism, so we should evaluate what each option claims about timing rules and the intracellular signaling that follows.
Option 1 states that STDP depends only on presynaptic firing rate and that precise timing relative to the postsynaptic spike is irrelevant. This is inaccurate because STDP is defined by the relative timing between presynaptic and postsynaptic spikes, with the direction and magnitude of synaptic change strongly dependent on whether the presynaptic event precedes or follows the postsynaptic event within a narrow time window. Simply relying on firing rate ignores the critical timing dependence.
Option 2 claims that when a postsynaptic spike precedes a presynaptic spike, LTP is induced due to back-propagating action potentials inserting AMPA receptors. While back-propagating action potentials can contribute to synaptic changes under certain conditions, the classic STDP rule emphasizes that postsynaptic-spike–preceding presynaptic spike typically leads to LTD within the canonical timing window, and LTP is more reliably associated with presynaptic-before-postsynaptic timing. Moreover, the mechanism described (back-propagating APs inserting AMPA receptors) is an oversimplification and not the standard STDP rule.
Option 3 explicitly describes the canonical STDP timing rule: if a presynaptic spike precedes a postsynaptic spike by a few–tens of milliseconds, the synapse undergoes LTP via large NMDA-receptor–dependent Ca²⁺ influx and kinase activation; if the order is reversed (post before pre) within a similar window, the synapse undergoes LTD via smaller Ca²⁺ signals and phosphatase activation. This matches well-established experimental data: presynaptic-before-postsynaptic timing leads to LTP through substantial Ca²⁺ entry through NMDA receptors and activation of calcium/calmodulin-dependent kinases, while the opposite order yields LTD through more modest Ca²⁺ signals activating phosphatases.
Option 4 states that any two spikes within ~100 ms always produce potentiation, regardless of order, because temporal proximity alone strengthens synapses. This is incorrect because STDP is highly sensitive to the order of spikes; identical short intervals with reversed order do not necessarily produce potentiation and can produce LTD instead. The claim of order-insensitive potentiation ignores the core timing dependence that defines STDP.
In summary, evaluating the claims against STDP biology shows that Option 3 best aligns with the established mechanism, while Options 1, 2, and 4 misstate timing dependence, intracellular signaling, or both. The accuracy hinges on recognizing that the direction and magnitude of plasticity in STDP depend on the precise pre-before-post versus post-before-pre sequence within a restricted time window, with NMDA receptor–mediated Ca²⁺ signaling and kinase/phosphatase pathways driving LTP and LTD, respectively.

Which statement best describes spike-timing–dependent plasticity (STDP) and its primary cellular mechanism?单项选择题

类似问题

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？

Calcium elevation in the postsynaptic spine is a critical trigger for activity‑dependent synaptic plasticity. Which ONE of the following outcomes is most directly initiated by increases in postsynaptic calcium at excitatory synapses?

What is synaptic plasticity?

What is the effect of the Stau2 protein?

In Aplysia, long-term sensitisation differs from short-term sensitisation primarily because it:

Which of the following best characterizes the canonical mechanism of NMDA receptor–dependent long-term depression (LTD) in hippocampal CA1 neurons?

In the context of short-term plasticity what causes facilitation?

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