Question

The image above shows three brain areas prior to an associative LTP experiment. There is a strong connection between Area A and Area C, and there is a weak connection between Area B and Area C. At this point, if we stimulated A we would see [ Select ] , and if we stimulated B we would see [ Select ] .

1) a strong response in Area C
2) a weak response in Area C
3) no response in Area C

Answer 1

In an associative LTP experiment, stimulation of Area A, which has a strong connection to Area C, would lead to a strong response in Area C due to enhanced synaptic strength. Conversely, stimulating Area B, with its weak connection to Area C, would produce a weak response in Area C due to less synaptic strengthening.

Step-by-step explanation:

In an associative Long-Term Potentiation (LTP) experiment where there is a strong connection between Area A and Area C, stimulating Area A would likely yield a strong response in Area C because the synaptic strength between these regions has been increased through the insertion of more AMPA receptors into the postsynaptic membrane of Area C. This enhancement is due to previous associative activity conforming to the Hebbian principle "cells that fire together wire together." Therefore, when Area A is stimulated, more positive ions will enter Area C, causing a stronger excitatory postsynaptic potential (EPSP).

Conversely, when Area B, which has a weak connection with Area C, is stimulated, it would result in a weak response in Area C. Since LTP has not sufficiently occurred between Area B and C, there are fewer AMPA receptors at the synapse in Area C to respond to glutamate released from Area B, so less depolarizing current is generated. Thus, the postsynaptic neuron is less likely to reach the threshold for action potential generation.