In an experiment that showed that CaMKII was involved in synaptic plasticity, one input was stimulated at high frequency (S1), which induced LTP. LTP was not induced from a second input that was not stimulated at high frequency (S2). Later in the same experiment, constitutively CaMKII was injected into the cell body of the postsynaptic neuron and both inputs were stimulated. Stimulation of which input resulted in LTP and why? Choose all that apply.
A) Stimulation of S1 induced LTP because those synapses were already potentiated.
B) Stimulation of S1 did not induce LTP because it was occluded by prior LTP.
C) Stimulation of S2 induced LTP because of the presence of CaMKII that was paired with S2 stimulation.
D) Stimulation of S2 did not induce LTP because it was not previously potentiated.

Question

Quizplus · Accepted Answer

B) Stimulation of S1 did not induce LTP because it was occluded by prior LTP, meaning the synapses were already at a potentiated state and could not be further potentiated. C) Stimulation of S2 induced LTP because the presence of constitutively active CaMKII, when paired with stimulation, could induce LTP in synapses that were not previously potentiated.

In an Experiment That Showed That CaMKII Was Involved in Synaptic